Found 64 papers in cond-mat Hall viscosity is a non-dissipative viscosity occurring in systems with
broken time-reversal symmetry, such as quantum Hall phases and $p+ip$
superfluids. Despite Hall viscosity's expected ubiquity and past observations
in classical soft matter systems, it has yet to be measured experimentally in
any quantum phase of matter. Toward this end, we describe the observable
effects of Hall viscosity in a simple family of rotating Bose-Einstein
condensates of electrically neutral bosons, in which all of the bosons condense
into a single LLL orbital. Such phases are accessible to current cold atom
experiments, and we dub them lowest Landau level (LLL) superfluids. We
demonstrate that LLL superfluids possess a non-universal Hall viscosity,
leading to a range of observable consequences such as rotation of
vortex-antivortex dipoles and wave-vector dependent corrections to the speed of
sound. Furthermore, using a coherent state path integral approach, we present a
microscopic derivation of the Landau-Ginzburg equations of a LLL superfluid,
showing explicitly how Hall viscosity enters.
Correlated disorder has been shown to enhance and modulate magnetic,
electrical, dipolar, electrochemical and mechanical properties of materials.
However, the possibility of obtaining novel optical and opto-electronic
properties from such correlated disorder remains an open question. Here, we
show unambiguous evidence of correlated disorder in the form of anisotropic,
sub-angstrom-scale atomic displacements modulating the refractive index tensor
and resulting in the giant optical anisotropy observed in BaTiS3, a
quasi-one-dimensional hexagonal chalcogenide. Single crystal X-ray diffraction
studies reveal the presence of antipolar displacements of Ti atoms within
adjacent TiS6 chains along the c-axis, and three-fold degenerate Ti
displacements in the a-b plane. 47/49Ti solid-state NMR provides additional
evidence for those Ti displacements in the form of a three-horned NMR lineshape
resulting from low symmetry local environment around Ti atoms. We used scanning
transmission electron microscopy to directly observe the globally disordered Ti
a-b plane displacements and find them to be ordered locally over a few unit
cells. First-principles calculations show that the Ti a-b plane displacements
selectively reduce the refractive index along the ab-plane, while having
minimal impact on the refractive index along the chain direction, thus
resulting in a giant enhancement in the optical anisotropy. By showing a strong
connection between correlated disorder and the optical response in BaTiS3, this
study opens a pathway for designing optical materials with high refractive
index and functionalities such as a large optical anisotropy and nonlinearity.
Employing flux-grown single crystal WSe$_2$, we report charge carrier
scattering behaviors measured in $h$-BN encapsulated monolayer field effect
transistors. We perform quantum transport measurements across various hole
densities and temperatures and observe an increase in transport mobility $\mu$
as a function of hole density in the degenerately doped sample. This unusual
behavior can be explained by energy dependent scattering amplitude of strong
defects calculated using the T-matrix approximation. Utilizing long mean-free
path ($>$500 nm), we demonstrate the high quality of our electronic devices by
showing quantized conductance steps from an electrostatically-defined quantum
point contact. Our results show the potential for creating ultra-high quality
quantum optoelectronic devices based on atomically thin semiconductors.
The discovery and manipulation of topological Hall effect (THE), an abnormal
magnetoelectric response mostly related to the Dzyaloshinskii-Moriya
interaction (DMI), are promising for next-generation spintronic devices based
on topological spin textures such as magnetic skyrmions. However, most
skyrmions and THE are stabilized in a narrow temperature window either below or
over room temperature with high critical current manipulation. It is still
elusive and challenging to achieve large THE with both wide temperature window
till room temperature and low critical current manipulation. Here, by using
controllable, naturally-oxidized, sub-20 and sub-10 nm 2D van der Waals
room-temperature ferromagnetic Fe3GaTe2-x crystals, robust 2D THE with
ultrawide temperature window ranging in three orders of magnitude from 2 to 300
K is reported, combining with giant THE of ~5.4 micro-ohm cm at 10 K and ~0.15
micro-ohm cm at 300 K which is 1-3 orders of magnitude larger than that of all
known room-temperature 2D skyrmion systems. Moreover, room-temperature
current-controlled THE is also realized with a low critical current density of
~6.2*10^5 A cm^-2. First-principles calculations unveil natural
oxidation-induced highly-enhanced 2D interfacial DMI reasonable for robust
giant THE. This work paves the way to room-temperature, electrically-controlled
2D THE-based practical spintronic devices.
We establish rigorous connections between quantum circuit complexity and
approximate quantum error correction (AQEC) properties, covering both
all-to-all and geometric scenarios including lattice systems. To this end, we
introduce a type of code parameter that we call subsystem variance, which is
closely related to the optimal AQEC precision. Our key finding is that if the
subsystem variance is below an $O(k/n)$ threshold then any state in the code
subspace must obey certain circuit complexity lower bounds, which identify
nontrivial ``phases'' of codes. Based on our results, we propose $O(k/n)$ as a
boundary between subspaces that should and should not count as AQEC codes. This
theory of AQEC provides a versatile framework for understanding the quantum
complexity and order of many-body quantum systems, offering new insights for
wide-ranging physical scenarios, in particular topological order and critical
quantum systems which are of outstanding importance in many-body and high
energy physics. We observe from various different perspectives that roughly
$O(1/n)$ represents a common, physically significant ``scaling threshold'' of
subsystem variance for features associated with nontrivial quantum order.
In topological materials, shielding of bulk and surface states by crystalline
symmetries has provided hitherto unknown access to electronic states in
condensed matter physics. Interestingly, photo-excited carriers relax on an
ultrafast timescale, demonstrating large transient mobility that could be
harnessed for the development of ultrafast optoelectronic devices. In addition,
these devices are much more effective than topologically trivial systems
because topological states are resilient to the corresponding
symmetry-invariant perturbations. By using optical pump probe measurements, we
systematically describe the relaxation dynamics of a topologically nontrivial
chiral single crystal, PtAl. Based on the experimental data on transient
reflectivity and electronic structures, it has been found that the carrier
relaxation process involves both acoustic and optical phonons with oscillation
frequencies of 0.06 and 2.94 THz, respectively, in picosecond time scale. PtAl
with a space group of $P$$2_{1}$3 allows only one non-zero susceptibility
element i.e. $d_{14}$, in second harmonic generation (SHG) with a large value
of 468(1) pm/V, which is significantly higher than that observed in standard
GaAs(111) and ZnTe(110) crystals. The intensity dependence of the SHG signal in
PtAl reveals a non-perturbative origin. The present study on PtAl provides
deeper insight into topological states which will be useful for ultrafast
optoelectronic devices.
Multi-functional manipulation of magnetic topological textures such as
skyrmions and bimerons in energy-efficient ways is of great importance for
spintronic applications, but still being a big challenge. Here, by
first-principles calculations and atomistic simulations, the creation and
annihilation of skyrmions/bimerons, as key operations for the reading and
writing of information in spintronic devices, are achieved in van der Waals
magnetoelectric CrISe/In2Se3 heterostructure via perpendicular strain or
electric field without external magnetic field. Besides, the bimeron-skyrmion
conversion, size modulation and the reversible magnetization switching from
in-plane to out-of-plane could also be realized in magnetic-field-free ways.
Moreover, the topological charge and morphology can be precisely controlled by
a small magnetic field. The strong Dzyaloshinskii-Moriya interaction and
tunable magnetic anisotropy energy in a wide window are found to play vital
roles in such energy efficient multi-functional manipulation, and the
underlying physical mechanisms are elucidated. Our work predicts the
CrISe/In2Se3 heterostructure being an ideal platform to address this challenge
in spintronic applications, and theoretically guides the low-dissipation
multi-functional manipulation of magnetic topological textures.
In recent years, non-Hermitian phases in classical and quantum systems have
garnered significant attention. In particular, their intriguing band geometry
offers a platform for exploring unique topological states and unconventional
quantum dynamics. However, their topological characterization becomes
particularly interesting and challenging in complex multiband systems. Here we
propose a decimation framework, which leverages real space renormalization
group to streamline the analysis of complex multiband non-Hermitian systems.
Our systematic approach allows us to probe different phases and transitions,
analyze bulk-boundary correspondence, formulate generalized Brillouin zones,
investigate open boundary spectra, survey non-Bloch van Hove singularities,
study disorder-induced effects, and explore tunable non-Hermitian flat band
physics. Additionally, our framework allows proposing a hypothesis about
quasi-one-dimensional bipartite non-Hermitian systems with flat bands,
demonstrating their decoupling into Su-Schrieffer-Heeger chains and compact
localized states across various models. Our work presents a powerful and
comprehensive framework for understanding the intricate properties of
non-Hermitian multiband systems, offering insights into the evolving landscape
of non-Hermitian topological physics.
The effect of magnetic STM-tip on electronic, magnetic and electronic
transport properties through the molecule junction STM-tip-Co/CoPc/Co(111), has
been investigated by mean of ab initio electronic structure calculations. The
spin transition has been studied by varying the distance (passing from the
tunneling regime to the contact regime) between the tip and the CoPc molecule
in both configurations, parallel and anti-parallel. Our calculation shows that
the transition of spin of the Co atom of CoPc molecule has led to a change of
the sign of the Magneto-Resistance (MR). It is also shown that the
characteristic I-V has been influenced by this spin-transition of central atom
of CoPc molecule.
Random packings of stiff rods are self-supporting mechanical structures
stabilized by their geometrical and topological complexity. To understand why,
we deploy X-ray computerized tomography to unveil the structure of the packing.
This allows us to define and directly visualize the spatial variations in
"entanglement," a mesoscopic field that characterizes the local average
crossing number, a measure of the topological complexity of the packing. We
show that the entanglement field has information that is distinct from the
density, orientational order, and contact distribution of the packing. We find
that increasing the aspect ratio of the constituent rods in a packing leads to
an abrupt change in the entanglement, correlated with a sharp transition in the
mechanical response of the packing. This leads to an entanglement phase diagram
for the mechanical response of dense rod packings that is likely relevant for a
broad range of problems that goes beyond our specific study.
Phononic engineering at GHz frequencies form the foundation of microwave
acoustic filters, high-speed acousto-optic modulators, and quantum transducers.
THz phononic engineering could lead to acoustic filters and modulators at
higher bandwidth and speed, as well as quantum circuits operating at higher
temperatures. It can also enable new ways to manipulate and control thermal
transport, as THz acoustic phonons are the main heat carriers in nonmetallic
solids. Despite its potential, methods for engineering THz phonons have been
little explored due to the challenges of achieving the required material
control at sub-nanometer precision and efficient phonon coupling at THz
frequencies. Here, we demonstrate efficient generation, detection, and
manipulation of THz phonons through precise integration of atomically thin
layers in van der Waals heterostructures. We employ few-layer graphene as an
ultrabroadband transducer, converting fs near-infrared pulses to broadband
acoustic phonon pulses with spectral content up to 3 THz. A single layer of
WSe$_2$ is used as a sensor, where high-fidelity readout is enabled by the
exciton-phonon coupling and strong light-matter interactions. By combining
these capabilities in a single van der Waals heterostructure and detecting
responses to incident mechanical waves, we performed THz phononic spectroscopy,
similar to conventional optical spectroscopy which detects responses to
incident electromagnetic waves. We demonstrate high-Q THz phononic cavities
using hBN stacks. We further show that a single layer of WSe$_2$ embedded in
hBN can efficiently block the transmission of THz phonons. By comparing our
measurements to a nanomechanical model, we obtain the important force constants
at the heterointerfaces. Our results could enable THz phononic metamaterials
based on van der Waals heterostructures, as well as novel routes for thermal
engineering.
We propose an extended Bogoliubov transformation in real space for spinless
fermions, based on which a class of Kitaev chains of length $2N$ with zero
chemical potential can be mapped to two independent Kitaev chains of length
$N$. It provides an alternative way to investigate a complicated system from
the result of relatively simple systems. We demonstrate the implications of
this decomposition by a Su-Schrieffer-Heeger (SSH) Kitaev model, which supports
rich quantum phases. The features of the system, including the groundstate
topology and nonequilibrium dynamics, can be revealed directly from that of
sub-Kitaev chains. Based on this connection, two types of
Bardeen-Cooper-Schrieffer (BCS)-pair order parameters are introduced to
characterize the phase diagram, showing the ingredient of two different BCS
pairing modes. Analytical analysis and numerical simulations show that the
real-space decomposition for the ground state still holds true approximately in
presence of finite chemical potential in the gapful regions.
We investigate through numerical simulations how a two-dimensional crystal
yields and flows under an applied shear. We focus over a range that allows us
to both address the response in the limit of an infinitesimal shear rate and
describe the phase behavior of the system at a finite shear rate. In doing so,
we carefully discuss the role of the topological defects and of the finite-size
effects. We map out the whole phase diagram of the flowing steady state in the
plane formed by temperature and shear rate. Shear-induced melting of the
two-dimensional crystal is found to proceed in two steps: first, the solid
loses long-range bond-orientational order and flows, even for an infinitesimal
shear rate (in the thermodynamic limit). The resulting flowing hexatic phase
then melts to a flowing, rather isotropic, liquid at a finite shear rate that
depends on temperature. Finally, at a high shear rate, a third regime
corresponding to a strongly anisotropic string-like flowing phase appears.
We report the growth of high-quality GaN epitaxial thin films on
graphene-coated c-sapphire substrates using pulsed-mode metalorganic
vapor-phase epitaxy, together with the fabrication of freestanding GaN films by
simple mechanical exfoliation for transferable light-emitting diodes (LEDs).
High-quality GaN films grown on the graphene-coated sapphire substrates were
easily lifted off using thermal release tape and transferred onto foreign
substrates. Furthermore, we revealed that the pulsed operation of ammonia flow
during GaN growth was a critical factor for the fabrication of high-quality
freestanding GaN films. These films, exhibiting excellent single crystallinity,
were utilized to fabricate transferable GaN LEDs by heteroepitaxially growing
InxGa1-xN/GaN multiple quantum wells and a p-GaN layer on the GaN films,
showing their potential application in advanced optoelectronic devices.
Exploring various topological states (TS) and topological phase transitions
(TPT) has attracted great attention in condensed matter physics. However, so
far, there is rarely a typical material system that can be used as a platform
to study the TS and TPT as the system transforms from one-dimensional (1D)
nanoribbons to two-dimensional (2D) sheet then to three-dimensional (3D) bulk.
Here, we first propose that some typical TS in 1D, 2D, and 3D systems can be
realized in a tight-binding (TB) model. Following the TB model and further
based on first-principles electronic structure calculations, we demonstrate
that the structurally stable (4,0) carbon nanotube derivatives are an ideal
platform to explore the semiconductor/nodal-point semimetal states in 1D
nanoribbons [1D-(4,0)-C16H4 and 1D-(4,0)-C32H4], nodal-ring semimetal state in
2D sheet [2D-(4,0)-C16], and nodal-cage semimetal state in 3D bulk
[3D-(4,0)-C16]. Furthermore, we calculate the characteristic band structures
and the edge/surface states of 2D-(4,0)-C16 and 3D-(4,0)-C16 to confirm their
nontrivial topological properties. Our work not only provides new excellent 2D
and 3D members for the topological carbon material family, but also serves as
an ideal template for the study of TS and TPT with the change of system
dimension.
When modeling charge dynamics in a chain of N sites at a temperature T, a
Langevin thermostat and a Hamiltonian system, i.e., a chain heated to a given
temperature before charge is injected, are compared. It is shown that the
polaron disruption occurs in the same range of values of the thermal energy NT,
however, T is not given by the initial data, but obtained after simulation from
the average kinetic energy. For large T, the results averaged over a set of
trajectories in a system with a Langevin thermostat and the results averaged
over time for a Hamiltonian system are close, which does not contradict the
Ergodic hypothesis.
Lithium disilicate glasses and glass-ceramics are good potential candidates
for biomedical applications and solid-state batteries, and serve as models of
nucleation and crystal growth. Moreover, these glasses exhibit a phase
separation that influences their nucleation and crystallization behavior. The
atomistic mechanisms of the phase separation and their pressure dependence are
unclear so far. Here, we used molecular dynamics simulations supported by
experiments to assess the spatial heterogeneity of lithium disilicate glasses
prepared under pressure. We show that the glass heterogeneity decreases with
increasing the cooling pressure and almost disappears at pressures around 30
GPa. The origin of the heterogeneity is due to the attraction between Li
cations to form clustering channels, which decreases with pressure. Through our
results, we hope to provide valuable insights and guidance for making
glass-ceramics with controlled crystallization.
Machine-learned potentials (MLPs) have become a popular approach of modelling
interatomic interactions in atomistic simulations, but to keep the
computational cost under control, a relatively short cutoff must be imposed,
which put serious restrictions on the capability of the MLPs for modelling
relatively long-ranged dispersion interactions. In this paper, we propose to
combine the neuroevolution potential (NEP) with the popular D3 correction to
achieve a unified NEP-D3 model that can simultaneously model relatively
short-ranged bonded interactions and relatively long-ranged dispersion
interactions. We show the improved descriptions of the binding and sliding
energies in bilayer graphene can be obtained by the NEP-D3 approach compared to
the pure NEP approach. We implement the D3 part into the GPUMD package such
that it can be used out of the box for many exchange-correlation functionals.
As a realistic application, we show that dispersion interactions result in
approximately a 10% reduction in thermal conductivity for three typical
metal-organic frameworks.
The topological electronic structure of crystalline materials often gives
rise to intriguing surface states, such as Dirac surface states in topological
insulators, Fermi arc surface states in Dirac semimetals, and topological
superconductivity in iron-based superconductors. Recently, rhombohedral
multilayer graphene has emerged as a promising platform for exploring exotic
surface states due to its hosting of topologically protected surface flat bands
at low energy, with the layer-dependent energy dispersion. These flat bands can
promote electron correlations, leading to a plethora of quantum phenomena,
including spontaneous symmetry breaking, superconductivity, ferromagnetism, and
topological Chern insulators. Nevertheless, the intricate connection between
the surface flat bands in rhombohedral multilayer graphene and the highly
dispersive high-energy bands hinders the exploration of correlated surface
states. Here, we present a method to isolate the surface flat bands of
rhombohedral heptalayer (7L) graphene by introducing moire superlattices. The
pronounced screening effects observed in the moire potential-modulated
rhombohedral 7L graphene indicate its essential three-dimensional (3D) nature.
The isolated surface flat bands favor correlated states on the surface in the
regions away from charge-neutrality points. Most notably, we observe tunable
surface ferromagnetism, manifested as an anomalous Hall effect with hysteresis
loops, which is achieved by polarizing surface states using finite displacement
fields. Our work establishes rhombohedral multilayer graphene moire
superlattice as a unique 3D system for exploring correlated surface states.
We propose the rotational dynamics of the intralayer and interlayer excitons
with their inherent momenta of inertia in the monolayer and bilayer transition
metal dichalcogenides, respectively, where the new chirality of exciton is
endowed by the rotational angular momentum, namely, the formations of left- and
right-handed excitons at the +K and -K valleys, respectively. We find that
angular momenta exchange between excitons and its surrounding phononic bath
result in the large fluctuation of the effective g-factor and the asymmetry of
valley Zeeman splitting observed in most recently experiments, both of which
sensitively depend on the magnetic moments provided by the phononic
environment. This rotating exciton model not only proposes a new controllable
knob in valleytronics, but opens the door to explore the angular momentum
exchange of the chiral quasiparticles with the many-body environment.
The quantum anomalous Hall state with a large band gap and a high Chern
number is significant for practical applications in spintronics. By performing
first-principles calculations, we investigate electronic properties of the
fully fluorinated 1T-MoSe$_{2}$ monolayer. Without considering the spin-orbit
coupling, the band structure demonstrates single-spin semi-metallic properties
and the trigonal warping around $K_{\pm}$ valleys. The introduction of the
spin-orbit coupling opens considerable band gaps of $117.2$ meV around the two
valleys, leading to a nontrivial quantum anomalous Hall state with a Chern
number of $|C|=2$, which provides two chiral dissipationless transport channels
from topological edge states and associated quantized anomalous Hall
conductivity. In addition, an effective model is constructed to describe the
low-energy physics of the monolayer. Our findings in the MoSe$_{2}$F$_{2}$
monolayer sheds light on large-gap quantum anomalous Hall states in
two-dimensional materials with the chemical functionalization, and provides
opportunities in designing low-power and noise-tolerant spintronic devices.
We propose an effective lattice model for the Moir\'e structure of twisted
bilayer dice lattice. We find that there are flat bands near zero energy level
at any twist angle besides the magic ones. The flat bands contain both bands
with zero Chern number which are originated from the destructive interference
of the dice lattice and the topological non-trivial ones at the magic angle.
The existence of the flat bands can be detected from the peak-splitting fine
structure of the optical conductance at all angles, while the transition peaks
do not split and only occur at magic angles in twisted bilayer graphene.
Half a century ago, T. Kibble proposed a scenario for topological defect
formation from symmetry breaking during the expansion of the early Universe. W.
Zurek later crystallized the concept to superfluid helium, predicting a
power-law relation between the number of quantum vortices and the rate at which
the system passes through the lambda transition. Here, we report the
observation of Kibble-Zurek scaling in a homogeneous, strongly interacting
Fermi gas undergoing a superfluid phase transition. We investigate the
superfluid transition using two distinct control parameters: temperature and
interaction strength. The microscopic physics of condensate formation is
markedly different for the two quench parameters, signaled by their two orders
of magnitude difference in the condensate formation timescale. However,
regardless of the thermodynamic direction in which the system passes through a
phase transition, the Kibble-Zurek exponent is identically observed to be about
0.68 and shows good agreement with theoretical predictions that describe
superfluid phase transitions. This work demonstrates the gedanken experiment
Zurek proposed for liquid helium that shares the same universality class with
strongly interacting Fermi gases.
We investigate the optical conductivity, along with longitudinal and
transverse conductivities, in buckled hexagonal lattice such as silicene
subjected to both an in-plane magnetic field and a perpendicular electric
field. In this model, we neglect the effect of the spin-orbit interaction,
which is of a smaller order compared to the strong staggered potential and the
next-nearest hoping energy. The orientations of the in-plane magnetic field and
the perpendicular electric field give rise to a non-uniform, tunable gap. The
Chern number for each valley degree of freedom deviates from being constant but
remains steady when summed over the entire Brillouin zone. The longitudinal and
transverse currents, in the case of a specific valley, can be selected by
adjusting the direction of the electric field in the semimetal phase.
Furthermore, the defining characteristics of topological phases induces the
rapid change in longitudinal conductivity when varying the angle of orientation
of the in-plane magnetic field under monochromatic light, and perfect valley
filtering in transverse conductivity. The transverse current associated with a
specific valley can be selected when the angle of orientation satisfies the
specific conditions. This investigation paves the way for materials design with
valley-locked current, using a specific orientation of the in-plane magnetic
field.
In this work, we introduce a generalization of the Landauer bound for erasure
processes that stems from absolutely irreversible dynamics. Assuming that the
erasure process is carried out in an absolutely irreversible way so that the
probability of observing some trajectories is zero in the forward process but
finite in the reverse process, we derive a generalized form of the bound for
the average erasure work, which is valid also for imperfect erasure and
asymmetric bits. The generalized bound obtained is tighter or, at worst, as
tight as existing ones. Our theoretical predictions are supported by numerical
experiments and the comparison with data from previous works.
Materials with kagome lattice have attracted significant research attention
due to their nontrivial features in energy bands. In this work, we
theoretically investigate the evolution of electronic band structures of kagome
lattice in response to uniaxial strain using both a tight-binding model and an
antidot model based on a periodic muffin-tin potential. It is found that the
Dirac points move with applied strain. Furthermore, the flat band of unstrained
kagome lattice is found to develop into a highly anisotropic shape under a
stretching strain along y direction, forming a partially flat band with a
region dispersionless along ky direction while dispersive along kx direction.
Our results shed light on the possibility of engineering the electronic band
structures of kagome materials by mechanical strain.
Quantum Spin Hall (QSH) insulators possess distinct helical in-gap states,
enabling their edge states to act as one-dimensional conducting channels when
backscattering is prohibited by time-reversal symmetry. However, it remains
challenging to achieve high-performance combinations of nontrivial topological
QSH states with superconductivity for applications and requires understanding
of the complicated underlying mechanisms. Here, our experimental observations
for a novel superconducting phase in the pressurized QSH insulator Ta2Pd3Te5 is
reported, and the high-pressure phase maintains its original ambient pressure
lattice symmetry up to 45 GPa. Our in-situ high-pressure synchrotron X-ray
diffraction, electrical transport, infrared reflectance, and Raman spectroscopy
measurements, in combination with rigorous theoretical calculations, provide
compelling evidence for the association between the superconducting behavior
and the abnormal densified phase. The isostructural transition was found to
modify the topology of the Fermi surface directly, accompanied by a fivefold
amplification of the density of states at 20 GPa compared to ambient pressure,
which synergistically fosters the emergence of robust superconductivity. A
profound comprehension of the fascinating properties exhibited by the
compressed Ta2Pd3Te5 phase is achieved, highlighting the extraordinary
potential of van der Waals (vdW) QSH insulators for exploring and investigating
high-performance electronic advanced devices under extreme conditions.
(In,Ga) alloy droplets are used to catalyse the growth of (In,Ga)As nanowires
by molecular beam epitaxy on Si(111) substrates. The composition, morphology
and optical properties of these nanowires can be tuned by the employed
elemental fluxes. To incorporate more than 10% of In, a high In/(In+Ga) flux
ratio above 0.7 is required. We report a maximum In content of almost 30% in
bulk (In,Ga)As nanowires for an In/(In+Ga) flux ratio of 0.8. However, with
increasing In/(In+Ga) fl ux ratio, the nanowire length and diameter are notably
reduced. Using photoluminescence and cathodoluminescence spectroscopy on
nanowires covered by a passivating (In,Al)As shell, two luminescence bands are
observed. A significant segment of the nanowires shows homogeneous emission,
with a wavelength corresponding to the In content in this segment, while the
consumption of the catalyst droplet leads to a spectrally-shifted emission band
at the top of the nanowires. The (In,Ga)As nanowires studied in this work
provide a new approach for the integration of infrared emitters on Si
platforms.
We propose a theory, that we call the \textit{mode-shell correspondence},
which relates the topological zero-modes localised in phase space to a
\textit{shell} invariant defined on the surface forming a shell enclosing these
zero-modes. We show that the mode-shell formalism provides a general framework
unifying important results of topological physics, such as the bulk-edge
correspondence, higher-order topological insulators, but also the Atiyah-Singer
and the Callias index theories. In this paper, we discuss the already rich
phenomenology of chiral symmetric Hamiltonians where the topological quantity
is the chiral number of zero-dimensionial zero-energy modes. We explain how, in
a lot of cases, the shell-invariant has a semi-classical limit expressed as a
generalised winding number on the shell, which makes it accessible to
analytical computations.
The growth of bilayers of two-dimensional (2D) materials on conventional 3D
semiconductors results in 2D/3D hybrid heterostructures, which can provide
additional advantages over more established 3D semiconductors while retaining
some specificities of 2D materials. Understanding and exploiting these
phenomena hinge on knowing the electronic properties and the hybridization of
these structures. Here, we demonstrate that rhombohedral-stacked bilayer (AB
stacking) can be obtained by molecular beam epitaxy growth of tungsten
diselenide (WSe2) on gallium phosphide (GaP) substrate. We confirm the presence
of 3R-stacking of the WSe2 bilayer structure using scanning transmission
electron microscopy (STEM) and micro-Raman spectroscopy. Also, we report
high-resolution angle-resolved photoemission spectroscopy (ARPES) on our
rhombohedral-stacked WSe2 bilayer grown on GaP(111)B substrate. Our ARPES
measurements confirm the expected valence band structure of WSe2 with the band
maximum located at the gamma point of the Brillouin zone. The epitaxial growth
of WSe2 on GaP(111)B heterostructures paves the way for further studies of the
fundamental properties of these complex materials, as well as prospects for
their implementation in devices to exploit their promising electronic and
optical properties.
Semiconductor quantum dots in close proximity to superconductors may provoke
localized bound states within the superconducting energy gap known as
Yu-Shiba-Rusinov (YSR) state, which is a promising candidate for constructing
Majorana zero modes and topological qubits. Side-coupled double quantum dot
systems are ideal platforms revealing the secondary proximity effect. Numerical
renormalization group calculations show that, if the central quantum dot can be
treated as a noninteracting resonant level, it acts as a superconducting medium
due to the ordinary proximity effect. The bound state in the side dot behaves
as the case of a single impurity connected to two superconducting leads. The
side dot undergoes quantum phase transitions between a singlet state and a
doublet state as the Coulomb repulsion, the interdot coupling strength, or the
energy level sweeps. Phase diagrams indicate that the phase boundaries could be
well illustrated by $\Delta \approx c {T_{K2}}$ in all cases, with $\Delta$ is
the superconducting gap, $T_{K2}$ is the side Kondo temperature and $c$ is of
the order $1.0$. These findings offer valuable insights into the secondary
proximity effect, and show great importance for designing superconducting
quantum devices.
A Bilayer of semiconducting 2D electronic systems has long been a versatile
platform to study electronic correlation with tunable interlayer tunneling,
Coulomb interactions and layer imbalance. In the natural graphite bilayer,
Bernal-stacked bilayer graphene (BBG), the Landau level gives rise to an
intimate connection between the valley and layer. Adding a moire superlattice
potential enriches the BBG physics with the formation of topological minibands,
potentially leading to tunable exotic quantum transports. Here, we present
magnetotransport measurements of a high-quality bilayer graphene-hexagonal
boron nitride (hBN) heterostructure. The zero-degree alignment generates a
strong moire superlattice potential for the electrons in BBG and the resulting
Landau fan diagram of longitudinal and Hall resistance displays a Hofstadter
butterfly pattern with an unprecedented level of detail. We demonstrate that
the intricate relationship between valley and layer degrees of freedom controls
the topology of moire-induced bands, significantly influencing the energetics
of interacting quantum phases in the BBG superlattice. We further observe
signatures of field-induced correlated insulators and clear fractional
quantizations of interaction driven topological quantum phases, such as
fractional Chern insulators. Our results highlight the BBG/hBN heterostructure
as an ideal platform for studying the delicate interplay between topology and
electron correlation.
Bogoliubov quasiparticles play a crucial role in understanding the behavior
of a superconductor at the nanoscale, particularly in a vortex lattice where
they are thought to be confined to the vortex cores. Here, we use scanning
tunneling noise microscopy, which can locally quantify quasiparticles by
measuring the effective charge, to observe and image delocalized quasiparticles
around vortices in NbSe$_2$ for the first time. Our data reveals a strong
spatial variation of the quasiparticle concentration when tunneling into the
vortex state. We find that quasiparticle poisoning dominates when vortices are
less than four times the coherence length apart. Our results set a new length
scale for quasiparticle poisoning in vortex-based Majorana qubits and yield
information on the effect of vortices in quantum circuits. Finally, we can
describe our findings within the Ginzburg-Landau framework, but the microscopic
origin of the far-extending quasiparticles is yet to be understood.
The freshwater crisis is a growing concern and a pressing problem for the
world because of the increasing population, civilization, and rapid industrial
growth. The water treatment facilities are able to supply less than 1% of the
total water demand. Water desalination can be a potential solution to deal with
this alarming issue. Researchers have been exploring for quite some time to
find novel nano-enhanced membranes and manufacturing techniques to increase the
efficiency of the desalination process. Graphene and graphene modified
membranes showed huge potential as desalination membranes for comparatively
easier synthesis process and higher ion rejection rate than conventional filter
materials. Currently, single-layer Mos$_2$ has been discovered to have the same
potential of water permeability and ion rejection rate as graphene membrane in
a more energy-efficient way. For almost analogous nano porous structure of the
graphene membrane, almost 70% of the higher water flux is obtained from the
Mos$_2$ membrane. In this work, it has been shown that nano porous Mos$_2$
membranes provide a promising result for desalinating other salts of seawater
alongside NaCl. We have also observed the effect of variations in ions, pore
size, and pressure on water permeation and ion rejection rates in the water
desalination process. In this study, water permeation increased significantly
by increasing the pore area from 20{\AA} to 80{\AA}. The rate of water
filtration increases in proportion to both applied pressure and pore size,
sacrificing the ion rejection rate for the type of ions studied. A combination
of salt ions in the saline water for desalination has also been studied, where
the rejection rates for the different ions are separately represented for
various applied pressures. For seawater, the Mos$_2$ membrane has showed quite
promising performance in the study of ion variation.
The stability of fractional Chern insulators is widely believed to be
predicted by the resemblance of their single-particle spectra to Landau levels.
We investigate the scope of this geometric stability hypothesis by analyzing
the stability of a set of fractional Chern insulators that explicitly do not
have a Landau level continuum limit. By computing the many-body spectra of
Laughlin states in a generalized Hofstadter model, we analyze the relationship
between single-particle metrics, such as trace inequality saturation, and
many-body metrics, such as the magnitude of the many-body and entanglement
gaps. We show numerically that the geometric stability hypothesis holds for
Chern bands that are not continuously connected to Landau levels, as well as
conventional Chern bands, albeit often requiring larger system sizes to
converge for these configurations.
A generalized symmetry (defined by the algebra of local symmetric operators)
can go beyond group or higher group description. A theory of generalized
symmetry (up to holo-equivalence) was developed in terms of symmetry-TO -- a
bosonic topological order (TO) with gappable boundary in one higher dimension.
We propose a general method to compute the 2+1D symmetry-TO from the local
symmetric operators in 1+1D systems. Our theory is based on the commutant patch
operators, which are extended operators constructed as products and sums of
local symmetric operators. A commutant patch operator commutes with all local
symmetric operators away from its boundary. We argue that topological
invariants associated with anyon diagrams in 2+1D can be computed as contracted
products of commutant patch operators in 1+1D. In particular, we give concrete
formulae for several topological invariants in terms of commutant patch
operators. Topological invariants computed from patch operators include those
beyond modular data, such as the link invariants associated with the Borromean
rings and the Whitehead link. These results suggest that the algebra of
commutant patch operators is described by 2+1D symmetry-TO. Based on our
analysis, we also argue briefly that the commutant patch operators would serve
as order parameters for gapped phases with finite symmetries.
The possibility of selecting magnetic space groups by orienting the
magnetization direction or tuning magnetic orders offers a vast playground for
engineering symmetry protected topological phases in magnetic materials. In
this work, we study how selective tuning of symmetry and magnetism can
influence and control the resulting topology in a 2D magnetic system, and
illustrate such procedure in the ferromagnetic monolayer MnPSe$_3$. Density
functional theory calculations reveals a symmetry-protected accidental
semimetalic (SM) phase for out-of-plane magnetization which becomes an
insulator when the magnetization is tilted in-plane, reaching band gap values
close to $100$ meV. We identify an order-two composite antiunitary symmetry and
threefold rotational symmetry that induce the band crossing and classify the
possible topological phases using symmetry analysis, which we support with
tight-binding and $\mathbf{k}\cdot\mathbf{p}$ models. Breaking of inversion
symmetry opens a gap in the SM phase, giving rise to a Chern insulator. We
demonstrate this explicitly in the isostructural Janus compound
Mn$_2$P$_2$S$_3$Se$_3$, which naturally exhibits Rashba spin-orbit coupling
that breaks inversion symmetry. Our results map out the phase space of
topological properties of ferromagnetic transition metal phosphorus
trichalcogenides and demonstrate the potential of the magnetization-dependent
metal-to-insulator transition as a spin switch in integrated two-dimensional
electronics.
It is well-known that macroscopically-normalizable zero-energy wavefunctions
of spin-$\frac{1}{2}$ particles in a two-dimensional inhomogeneous magnetic
field are spin-polarized and exactly calculable with degeneracy equaling the
number of flux quanta linking the whole system. Extending this argument to
massless Dirac fermions subjected to magnetic fields that have \textit{zero}
net flux but are doubly periodic in real space, we show that there exist
\textit{only two} Bloch-normalizable zero-energy eigenstates, one for each spin
flavor. This result is immediately relevant to graphene multilayer systems
subjected to doubly-periodic strain fields, which at low energies, enter the
Hamiltonian as periodic pseudo-gauge vector potentials. Furthermore, we explore
various related settings including nonlinearly-dispersing band structure models
and systems with singly-periodic magnetic fields.
New developments in superconductivity, particularly through unexpected and
often astonishing forms of superconducting materials, continue to excite the
community and stimulate theory. It is now becoming clear that there are two
distinct platforms for superconductivity through natural and synthetic
materials. Indeed, the latter category has greatly expanded in the last decade
or so, with the discoveries of new forms of superfluidity in artificial
heterostructures and the exploitation of proximitization. The former category
continues to surprise through the Fe-based pnictides and chalcogenides, and
nickelates as well as others. It is the goal of this review to present this
two-pronged investigation into superconductors, with a focus on those which we
have come to understand belong somewhere between the BCS and Bose-Einstein
condensation (BEC) regimes. We characterize in detail the nature of this
``crossover" superconductivity, which is to be distinguished from crossover
superfluidity in atomic Fermi gases. In the process, we address the multiple
ways of promoting a system out of the BCS and into the BCS-BEC crossover regime
within the context of concrete experimental realizations. These involve natural
materials, such as organic conductors, as well as artificial, mostly
two-dimensional materials, such as magic-angle twisted bilayer and trilayer
graphene, or gate-controlled devices, as well as one-layer and interfacial
superconducting films. This work should be viewed as a celebration of BCS
theory by showing that even though this theory was initially implemented with
the special case of weak correlations in mind, it can in a very natural way be
extended to treat the case of these more exotic strongly correlated
superconductors.
The soft modes associated with continuous-order phase transitions are
associated with strong anharmonicity. This leads to the overdamped limit where
the phonon quasi-particle picture can breakdown. However, this limit is
commonly restricted to a narrow temperature range, making it difficult to
observe its signature feature, namely the breakdown of the inverse relationship
between the relaxation time and damping. Here we present a physically intuitive
picture based on the relaxation times of the mode coordinate and its conjugate
momentum, which at the instability approach infinity and the inverse damping
factor, respectively. We demonstrate this behavior for the cubic-to-tetragonal
phase transition of the inorganic halide perovskite CsPbBr$_3$ via molecular
dynamics, and show that the overdamped region extends almost 200 K above the
transition temperature. Further, we investigate how the dynamics of these soft
phonon modes change when crossing the phase transition.
The creation of moir\'e superlattices in twisted bilayers of two-dimensional
crystals has been utilised to engineer quantum material properties in graphene
and transition metal dichalcogenide (TMD) semiconductors. Here, we examine the
structural relaxation and electronic properties in small-angle twisted bilayers
of metallic NbSe$_2$. Reconstruction appears to be particularly strong for
misalignment angles $\theta_P$ < 2.9$^o$ and $\theta_{AP}$ < 1.2$^o$ for
parallel (P) and antiparallel (AP) orientation of monolayers' unit cells,
respectively. Multiscale modelling reveals the formation of domains and domain
walls with distinct stacking, for which density functional theory (DFT)
calculations are used to map the shape of the bilayer Fermi surface and the
relative phase of the CDW order in adjacent layers. We find a significant
modulation of interlayer coupling across the moir\'e superstructure and the
existence of preferred interlayer orientations of the CDW phase, necessitating
the nucleation of CDW discommensurations at superlattice domain walls.
By substituting S into single-layer FeSe/SrTiO3, chemical pressure is applied
to tune its paramagnetic state that is modeled as an incoherent superposition
of spin-spiral states. The resulting electronic bands resemble an ordered
checkerboard antiferromagnetic structure, consistent with angle-resolved
photoemission spectroscopy measurements. Scanning tunneling spectroscopy
reveals a gap evolving from U-shaped for FeSe to V-shaped for FeS with
decreasing size, attributed to a d-wave superconducting state for which nodes
emerge once the gap size is smaller than the effective spin-orbit coupling.
The non-Hermitian skin effect is a unique phenomenon in which an extensive
number of eigenstates are localized at the boundaries of a non-Hermitian
system. Recent studies show that the non-Hermitian skin effect is significantly
suppressed by magnetic fields. In contrast, we demonstrate that the
second-order skin effect (SOSE) is robust and can even be enhanced by magnetic
fields. Remarkably, SOSE can also be induced by magnetic fields from a trivial
non-Hermitian system that does not experience any skin effect at zero field.
These properties are intimately related to to the persistence and emergence of
topological line gaps in the complex energy spectrum in presence of magnetic
fields. Moreover, we show that a magnetic field can drive a non-Hermitian
system from a hybrid skin effect, where the first-order skin effect and SOSE
coexist, to pure SOSE. Our results describe a qualitatively new magnetic field
behavior of the non-Hermitian skin effect.
This work theoretically investigates \textcolor{black}{the stationary
properties} and the dynamics of the rotating quantum liquid droplets confined
in a two-dimensional symmetric anharmonic trap. Mimicking the quantum Hall
systems, the modified Gross-Pitaevskii equation with the inclusion of the
Lee-Huang-Yang nonlinear interaction is analytically solved, and the role of
the Landau-level mixing effect is addressed. \textcolor{black}{Via controlling
the nonlinear interaction and the rotation speed, the rotating quantum droplet
with multiply quantized vortex can be created, and the preference of the
energetically favored quantum states can be distinguished in the phase diagram.
To better interpret the underlying physics of the phase singularities, a brief
comparison of the rotating quantum droplet and the optical vortex is made. The
investigation of the long-term evolution of the rotating quantum droplets
confirms the stability of the quantum states. At certain rotation speeds, the
multi-periodic trajectories and breathings provide evidence of the emergence of
the collective excitation of the surface mode in the vortex state. For quantum
droplets carrying multiply quantized vortex, the microscopic snapshots of the
rotation field adjusted current density distribution show that the combined
nonlinear interaction and the anharmonic trapping potential can provide the
restoring force to lead the quantum droplet to a regular and stable revolution
and reach the dynamic equilibrium, revealing the signature of the generation of
superfluids in the new kind of low-dimensional quantum liquids.
Non-Hermitian quantum systems exhibit fascinating characteristics such as
non-Hermitian topological phenomena and skin effect, yet their studies are
limited by the intrinsic difficulties associated with their eigenvalue
problems, especially in larger systems and higher dimensions. In Hermitian
systems, the semiclassical theory has played an active role in analyzing
spectrum, eigenstate, phase, transport properties, etc. Here, we establish a
complex semiclassical theory applicable to non-Hermitian quantum systems by an
analytical continuation of the physical variables such as momentum, position,
time, and energy in the equations of motion and quantization condition to the
complex domain. Further, we propose a closed-orbit scheme and physical meaning
under such complex variables. We demonstrate that such a framework
straightforwardly yields complex energy spectra and quantum states, topological
phases and transitions, and even the skin effect in non-Hermitian quantum
systems, presenting an unprecedented perspective toward nontrivial
non-Hermitian physics, even with larger systems and higher dimensions.
Berry curvature multipoles appearing in topological quantum materials have
recently attracted much attention. Their presence can manifest in novel
phenomena, such as nonlinear anomalous Hall effects (NLAHE). The notion of
Berry curvature multipoles extends our understanding of Berry curvature effects
on the material properties. Hence, research on this subject is of fundamental
importance and may also enable future applications in energy harvesting and
high-frequency technology. It was shown that a Berry curvature dipole can give
rise to a 2nd order NLAHE in materials of low crystalline symmetry. Here, we
demonstrate a fundamentally new mechanism for Berry curvature multipoles in
antiferromagnets that are supported by the underlying magnetic symmetries.
Carrying out electric transport measurements on the kagome antiferromagnet
FeSn, we observe a 3rd order NLAHE, which appears as a transverse voltage
response at the 3rd harmonic frequency when a longitudinal a.c. current drive
is applied. Interestingly, this NLAHE is strongest at and above room
temperature. We combine these measurements with a scaling law analysis, a
symmetry analysis, model calculations, first-principle calculations, and
magnetic Monte-Carlo simulations to show that the observed NLAHE is induced by
a Berry curvature quadrupole appearing in the spin-canted state of FeSn. At a
practical level, our study establishes NLAHE as a sensitive probe of
antiferromagnetic phase transitions in other materials, such as moir\'e
superlattices, two-dimensional van der Waal magnets, and quantum spin liquid
candidates, that remain poorly understood to date. More broadly, Berry
curvature multipole effects are predicted to exist for 90 magnetic point
groups. Hence, our work opens a new research area to study a variety of
topological magnetic materials through nonlinear measurement protocols.
Entanglement is resolved in conformal field theory (CFT) with respect to
conformal families to all orders in the UV cutoff. To leading order,
symmetry-resolved entanglement is connected to the quantum dimension of a
conformal family, while to all orders it depends on null vectors. Criteria for
equipartition between sectors are provided in both cases. This analysis
exhausts all unitary conformal families. Furthermore, topological entanglement
entropy is shown to symmetry-resolve the Affleck-Ludwig boundary entropy.
Configuration and fluctuation entropy are analyzed on grounds of conformal
symmetry.
The opacity of graphene is known to be approximately given by the
fine-structure constant $\alpha$ times $\pi$. We point out the fact that the
opacity is roughly independent of the frequency and polarization of the light
can be attributed to the topological charge of the Dirac points. As a result,
one can literally see the topological charge by naked eyes from the opacity of
graphene, and moreover it implies that the fine-structure constant is
topologically protected. A similar analysis suggests that 3D topological
insulator thin films of any thickness also have opacity $\pi\alpha$ in the
infrared region owing to the topological surface states, indicating that one
can see the surface states by naked eyes through an infrared lens. For 3D Dirac
or Weyl semimetals, the optical absorption power is linear to the frequency in
the infrared region, with a linearity given by the fine-structure constant and
the topological charge of Weyl points.
It has recently been demonstrated that MoS2 with irregular interlayer
rotations can achieve an extreme anisotropy in the lattice thermal conductivity
(LTC), which is for example of interest for applications in waste heat
management in integrated circuits. Here, we show by atomic scale simulations
based on machine-learned potentials that this principle extends to other
two-dimensional materials including C and BN. In all three materials
introducing rotational disorder drives the through-plane LTC to the glass
limit, while the in-plane LTC remains almost unchanged compared to the ideal
bulk materials. We demonstrate that the ultralow through-plane LTC is connected
to the collapse of their transverse acoustic modes in the through-plane
direction. Furthermore, we find that the twist angle in periodic moir\'e
structures representing rotational order provides an efficient means for tuning
the through-plane LTC that operates for all chemistries considered here. The
minimal through-plane LTC is obtained for angles between 1 and 4 degree
depending on the material, with the biggest effect in MoS2. The angular
dependence is correlated with the degree of stacking disorder in the materials,
which in turn is connected to the slip surface. This provides a simple
descriptor for predicting the optimal conditions at which the LTC is expected
to become minimal.
The GW self-energy may become computationally challenging to evaluate because
of frequency and momentum convolutions. These difficulties were recently
addressed by the development of the multipole approximation (MPA) and the W-av
methods: MPA accurately approximates full-frequency response functions using a
small number of poles, while W-av improves the convergence with respect to the
k-point sampling in 2D materials. In this work we (i) present a theoretical
scheme to combine them, and (ii) apply the newly developed approach to the
paradigmatic case of graphene. Our findings show an excellent agreement of the
calculated QP band structure with angle resolved photoemission spectroscopy
(ARPES) data. Furthermore, the computational efficiency of MPA and W-av allows
us to explore the logarithmic renormalization of the Dirac cone. To this aim,
we develop an analytical model, derived from a Dirac Hamiltonian, that we
parameterize using ab-initio data. The comparison of the models obtained with
PPA and MPA results highlights an important role of the dynamical screening in
the cone renormalization.
Advances in hybrid fractional quantum Hall (FQH)-superconductor platforms
pave the way for realisation of parafermionic modes. We analyse signatures of
these non-abelian anyons in transport measurements across devices with
$\mathbb{Z}_6$ parafermions (PFs) coupled to an external electrode. Simulating
the dynamics of these open systems by a stochastic quantum jump method, we show
that a current readout over sufficiently long times constitutes a projective
measurement of the fractional charge shared by two PFs. Interaction of these
topological modes with the FQH environment, however, may cause poisoning events
affecting this degree of freedom which we model by jump operators that describe
incoherent coupling of PFs with FQH edge modes. We analyse how this gives rise
to a characteristic three-level telegraph noise in the current, constituting a
very strong signature of PFs. We discuss also other forms of poisoning and
noise caused by interaction with fractional quasiparticles in the bulk of the
Hall system. We conclude our work with an analysis of four-PF devices, in
particular on how the PF fusion algebra can be observed in electrical transport
experiments.
The relativistic Foldy-Wouthuysen transformation is used for an advanced
description of planar graphene electrons in external fields and free
(2+1)-space. It is shown that the initial Dirac equation should by based on the
usual $(4\times4)$ Dirac matrices but not on the reduction of matrix dimensions
and the use of $(2\times2)$ Pauli matrices. The latter approach does not agree
with the experiment. The spin of graphene electrons is not the one-value spin
and takes the values $\pm1/2$. The exact Foldy-Wouthuysen Hamiltonian of a
graphene electron in uniform and nonuniform magnetic fields is derived. The
exact energy spectrum agreeing with the experiment and exact Foldy-Wouthuysen
wave eigenfunctions are obtained. These eigenfunctions describe multiwave
(structured) states in (2+1)-space. It is proven that the Hermite-Gauss beams
exist even in the free space. In the multiwave Hermite-Gauss states, graphene
electrons acquire nonzero effective masses dependent on a quantum number and
move with group velocities which are less than the Fermi velocity. Graphene
electrons in a static electric field also can exist in the multiwave
Hermite-Gauss states defining non-spreading coherent beams. These beams can be
accelerated and decelerated.
A rigorous methodology is developed for computing elastic fields generated by
experimentally observed defect structures within grains in a polycrystal that
has undergone tensile extension. An example application is made using a
near-field High Energy X-ray Diffraction Microscope measurement of a zirconium
sample that underwent $13.6\%$ tensile extension from an initially
well-annealed state. (Sub)grain boundary features are identified with apparent
disclination line defects in them. The elastic fields of these features
identified from the experiment are calculated.
While topological phases have been extensively studied in amorphous systems
in recent years, it remains unclear whether the random nature of amorphous
materials can give rise to higher-order topological phases that have no
crystalline counterparts. Here we theoretically demonstrate the existence of
higher-order topological insulators in two-dimensional amorphous systems that
can host more than six corner modes, such as eight or twelve corner modes.
Although individual sample configuration lacks crystalline symmetry, we find
that an ensemble of all configurations exhibits an average crystalline symmetry
that provides protection for the new topological phases. To characterize the
topological phases, we construct two topological invariants. Even though the
bulk energy gap in the topological phase vanishes in the thermodynamic limit,
we show that the bulk states near zero energy are localized, as supported by
the level-spacing statistics and inverse participation ratio. Our findings open
an avenue for exploring average symmetry protected higher-order topological
phases in amorphous systems without crystalline counterparts.
$\mathrm{Fe_{n=4,5}GeTe_2}$ exhibits quasi-two-dimensional properties as a
promising candidate for a near-room-temperature ferromagnet, which has
attracted great interest. In this work, we notice that the crystal lattice of
$\mathrm{Fe_{n=4,5}GeTe_2}$ can be approximately regarded as being stacked by
three bipartite crystal lattices. By combining the model Hamiltonians of
bipartite crystal lattices and first-principles calculations, we investigate
the electronic structure and the magnetism of $\mathrm{Fe_{n=4,5}GeTe_2}$. We
conclude that flat bands near the Fermi level originate from the bipartite
crystal lattices and that these flat bands are expected to lead to the
itinerant ferromagnetism in $\mathrm{Fe_{n=4,5}GeTe_2}$. Interestingly, we also
find that the magnetic moment of the Fe5 atom in $\mathrm{Fe_5 Ge Te_2}$ is
distinct from the other Fe atoms and is sensitive to the Coulomb interaction
$U$ and external pressure. These findings may be helpful to understand the
exotic magnetic behavior of $\mathrm{Fe_{n=4,5} Ge Te_2}$.
We study the scaling properties of the entanglement entropy (EE) near quantum
critical points in interacting random antiferromagnetic (AF) spin chains. Using
density-matrix renormalization group, we compute the half-chain EE near the
topological phase transition between Haldane and Random Singlet phases in a
disordered spin-1 chain. It is found to diverge logarithmically in system size
with an effective central charge $c_{\rm eff} = 1.17(4)$ at the quantum
critical point (QCP). Moreover, a scaling analysis of EE yields the correlation
length exponent $\nu=2.28(5)$. Our unbiased calculation establishes that the
QCP is in the universality class of the infinite-randomness fixed point
predicted by previous studies based on strong disorder renormalization group
technique. However, in the disordered spin-1/2 Majumdar-Ghosh chain, where a
valence bond solid phase is unstable to disorder, the crossover length exponent
obtained from a scaling analysis of EE disagrees with the expectation based on
Imry-Ma argument. We provide a possible explanation.
The appearance of van Hove singularities near the Fermi level leads to
prominent phenomena, including superconductivity, charge density wave, and
ferromagnetism. Here a bilayer Kagome lattice with multiple van Hove
singularities is designed and a novel borophene with such lattice
(BK-borophene) is proposed by the first-principles calculations. BK-borophene,
which is formed via three-center two-electron (3c-2e) sigma-type bonds, is
predicted to be energetically, dynamically, thermodynamically, and mechanically
stable. The electronic structure hosts both conventional and high-order van
Hove singularities in one band. The conventional van Hove singularity resulting
from the horse saddle is 0.065 eV lower than the Fermi level, while the
high-order one resulting from the monkey saddle is 0.385 eV below the Fermi
level. Both the singularities lead to the divergence of electronic density of
states. Besides, the high-order singularity is just intersected to a Dirac-like
cone, where the Fermi velocity can reach 1340000 m/s. The interaction between
the two Kagome lattices is critical for the appearance of high-order van Hove
singularities. The novel bilayer Kagome borophene with rich and intriguing
electronic structure offers an unprecedented platform for studying correlation
phenomena in quantum material systems and beyond.
We explore a hexagonal cavity that supports chiral topological whispering
gallery (CTWG) modes, formed by a gyromagnetic photonic crystal. This mode is a
special type of topologically protected optical mode that can propagate in
photonic crystals with chiral direction. Finite element method simulations show
that discrete edge states exist in the topological band gap due to the coupling
of chiral edge states and WG modes. Since the cavity only supports edge state
modes with group velocity in only one direction, it can purely generate
traveling modes and be immune to interference modes. In addition, we introduced
defects and disorder to test the robustness of the cavity, demonstrating that
the CTWG modes can be effectively maintained under all types of perturbations.
Our topological cavity platform offers useful prototype of robust topological
photonic devices. The existence of this mode can have important implications
for the design and application of optical devices.
Scattering dynamics influence the graphenes transport properties and inhibits
the charge carrier deterministic behaviour. The intra or inter-band scattering
mechanisms are vital for graphenes optical conductivity response under specific
considerations of doping. Here, we investigated the influence of scattering
systematically on optical conductivity using a semi-classical multiband
Boltzmann equation with inclusion of both electron-electron $\&$
electron-phonon collisions. We found unconventional characteristics of linear
optical response with a significant deviation from the universal conductivity
$\frac{e$^2$}{2$\hbar$}$ in doped monolayer graphene. This is explained through
phenomenological relaxation rates under low doping regime with dominant
intraband scattering. Such novel optical responses are vanished at high
temperatures or overdoping conditions due to strong Drude behaviour. With the
aid of approximations around Dirac points we have developed analytical
formalism for many body interactions and is in good agreement with the Kubo
approaches.
Semiconducting transition-metal dichalcogenides (TMDs) exhibit high mobility,
strong spin-orbit coupling, and large effective masses, which simultaneously
leads to a rich wealth of Landau quantizations and inherently strong electronic
interactions. However, in spite of their extensively explored Landau levels
(LL) structure, probing electron correlations in the fractionally filled LL
regime has not been possible due to the difficulty of reaching the quantum
limit. Here, we report evidence for fractional quantum Hall (FQH) states at
filling fractions 4/5 and 2/5 in the lowest LL of bilayer MoS$_{2}$, manifested
in fractionally quantized transverse conductance plateaus accompanied by
longitudinal resistance minima. We further show that the observed FQH states
sensitively depend on the dielectric and gate screening of the Coulomb
interactions. Our findings establish a new FQH experimental platform which are
a scarce resource: an intrinsic semiconducting high mobility electron gas,
whose electronic interactions in the FQH regime are in principle tunable by
Coulomb-screening engineering, and as such, could be the missing link between
atomically thin graphene and semiconducting quantum wells.
It is known that $n$-degenerate Landau levels with the same spin-valley
quantum number can be realized by $n$-layer graphene with rhombohedral stacking
under magnetic field $B$. We find that the wave functions of degenerate Landau
levels are concentrated at the surface layers of the multi-layer graphene if
the dimensionless ratio $\eta = \gamma_1/(v_F\sqrt{2e\hbar B/c}) \approx
9/\sqrt{B[\text{Tesla}]} \gg 1$, where $\gamma_1$ is the interlayer hopping
energy and $v_F$ the Fermi velocity of single-layer graphene. This allows us to
suggest that: 1) filling fraction $\nu=\frac12$ (or $\nu_n = 5\frac12$)
non-Abelian state with Ising anyon can be realized in three-layer graphene for
magnetic field $ B \in [ 2 , 9] $ Tesla; 2) filling fraction $\nu=\frac23$ (or
$\nu_n = 7\frac13$) non-Abelian state with Fibonacci anyon can be realized in
four-layer graphene for magnetic field $ B \in [ 5 , 9] $ Tesla. Here, $\nu$ is
the total filling fraction in the degenerate Landau levels, and $\nu_n$ is the
filling fraction measured from charge neutrality point which determines the
measured Hall conductance. We have assumed the following conditions to obtain
the above results: the exchange effect of Coulomb interaction polarizes the
$SU(4)$ spin-valley quantum number in the degenerate Landau levels and
effective dielectric constant $\epsilon \gtrsim 10$ to reduce the Coulomb
interaction. The high density of states of multi-layer graphene helps to reduce
the Coulomb interaction via screening.
The structures of multiply quantized vortices (MQVs) of an equal-population
atomic Fermi superfluid in a rotating spherical bubble trap approximated as a
thin shell are analyzed by solving the Bogoliubov-de Gennes (BdG) equation
throughout the BCS-Bose Einstein condensation (BEC) crossover. Consistent with
the Poincare-Hopf theorem, a pair of vortices emerge at the poles of the
rotation axis in the presence of azimuthal symmetry, and the compact geometry
provides confinement for the MQVs. While the single-vorticity vortex structure
is similar to that in a planar geometry, higher-vorticity vortices exhibit
interesting phenomena at the vortex center, such as a density peak due to
accumulation of a normal Fermi gas and reversed circulation of current due to
in-gap states carrying angular momentum, in the BCS regime but not the BEC
regime because of the subtle relations between the order parameter and density.
The energy spectrum shows the number of the in-gap state branches corresponds
to the vorticity of a vortex, and an explanation based on a topological
correspondence is provided.
Ultrafast light-matter interaction has emerged as a powerful tool to control
and probe the macroscopic properties of functional materials, especially
two-dimensional transition metal dichalcogenides which can form different
structural phases with distinct physical properties. However, it is often
difficult to accurately determine the transient optical constants. In this
work, we developed a near-infrared pump - terahertz to midinfrared (12-22 THz)
probe system in transmission geometry to measure the transient optical
conductivity in 2H-MoTe2 layered material. By performing separate measurements
on bulk and thin-film samples, we are able to overcome issues related to
nonuniform substrate thickness and penetration depth mismatch and to extract
the transient optical constants reliably. Our results show that photoexcitation
at 690 nm induces a transient insulator-metal transition, while photoexcitation
at 2 um has a much smaller effect due to the photon energy being smaller than
the band gap of the material. Combining this with a single-color pump-probe
measurement, we show that the transient response evolves towards 1T' phase at
higher flunece. Our work provides a comprehensive understanding of the
photoinduced phase transition in the 2H-MoTe2 system.
An important class of model Hamiltonians for investigation of topological
phases of matter consists of mobile, interacting particles on a lattice subject
to a semi-classical gauge field, as exemplified by the bosonic
Harper-Hofstadter model. A unique method for investigations of two-dimensional
quantum systems are the infinite projected-entangled pair states (iPEPS), as
they avoid spurious finite size effects that can alter the phase structure.
However, due to no-go theorems in related cases this was often conjectured to
be impossible in the past. In this letter, we show that upon variational
optimization the infinite projected-entangled pair states can be used to this
end, by identifying fractional Hall states in the bosonic Harper-Hofstadter
model. The obtained states are characterized by showing exponential decay of
bulk correlations, as dictated by a bulk gap, as well as chiral edge modes via
the entanglement spectrum.

Date of feed: Tue, 10 Oct 2023 00:30:00 GMT**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **Observable signatures of Hall viscosity in lowest Landau level superfluids. (arXiv:2310.04495v1 [cond-mat.quant-gas])**

Seth Musser, Hart Goldman, T. Senthil

**Giant Modulation of Refractive Index from Correlated Atomic-Scale Disorder. (arXiv:2310.04615v1 [cond-mat.mtrl-sci])**

Boyang Zhao, Guodong Ren, Hongyan Mei, Vincent C. Wu, Shantanu Singh, Gwan-Yeong Jung, Huandong Chen, Raynald Giovine, Shanyuan Niu, Arashdeep S. Thind, Jad Salman, Nick S. Settineri, Bryan C. Chakoumakos, Michael E. Manley, Raphael P. Hermann, Andrew R. Lupini, Miaofang Chi, Jordan A. Hachtel, Arkadiy Simonov, Simon J. Teat, Raphaële J. Clément, Mikhail A. Kats, J. Ravichandran, Rohan Mishra

**Transport Study of Charge Carrier Scattering in Monolayer WSe$_2$. (arXiv:2310.04624v1 [cond-mat.mes-hall])**

Andrew Y. Joe, Kateryna Pistunova, Kristen Kaasbjerg, Ke Wang, Bumho Kim, Daniel A. Rhodes, Takashi Taniguchi, Kenji Watanabe, James Hone, Tony Low, Luis A. Jauregui, Philip Kim

**Giant 2D Skyrmion Topological Hall Effect with Ultrawide Temperature Window and Low-Current Manipulation in 2D Room-Temperature Ferromagnetic Crystals. (arXiv:2310.04663v1 [cond-mat.mtrl-sci])**

Gaojie Zhang, Qingyuan Luo, Xiaokun Wen, Hao Wu, Li Yang, Wen Jin, Luji Li, Jia Zhang, Wenfeng Zhang, Haibo Shu, Haixin Chang

**Complexity and order in approximate quantum error-correcting codes. (arXiv:2310.04710v1 [quant-ph])**

Jinmin Yi, Weicheng Ye, Daniel Gottesman, Zi-Wen Liu

**Ultrafast Carrier Relaxation and Second Harmonic Generation in a Higher-Fold Weyl Fermionic System PtAl. (arXiv:2310.04717v1 [cond-mat.mes-hall])**

Vikas Saini, Ajinkya Punjal, Utkarsh Kumar Pandey, Ruturaj Vikrant Puranik, Vikash Sharma, Vivek Dwij, Kritika Vijay, Ruta Kulkarni, Soma Banik, Aditya Dharmadhikari, Bahadur Singh, Shriganesh Prabhu, A. Thamizhavel

**Manipulation of magnetic topological textures via perpendicular strain and polarization in van der Waals magnetoelectric heterostructure. (arXiv:2310.04810v1 [cond-mat.mtrl-sci])**

Zhong Shen, Shuai Dong, Xiaoyan Yao

**Non-Hermitian Topology and Flat Bands via an Exact Real Space Decimation Scheme. (arXiv:2310.04834v1 [cond-mat.mes-hall])**

Ayan Banerjee, Arka Bandyopadhyay, Ronika Sarkar, Awadhesh Narayan

**Electronic transport through the phtalocyanine molecule in atomic contacts Co. (arXiv:2310.04902v1 [quant-ph])**

Ali Jaafar, Tarek Khalil

**Entanglement transition in rod packings. (arXiv:2310.04903v1 [cond-mat.soft])**

Yeonsu Jung, Thomas Plumb-Reyes, Hao-Yu Greg Lin, L. Mahadevan

**Terahertz phonon engineering and spectroscopy with van der Waals heterostructures. (arXiv:2310.04939v1 [cond-mat.mes-hall])**

Yoseob Yoon, Zheyu Lu, Can Uzundal, Ruishi Qi, Wenyu Zhao, Sudi Chen, Qixin Feng, Kenji Watanabe, Takashi Taniguchi, Michael F. Crommie, Feng Wang

**Real-space decomposition of $p$-wave Kitaev chain. (arXiv:2310.05006v1 [cond-mat.str-el])**

D. K. He, E. S. Ma, Z. Song

**Shear-Induced Phase Behavior and Topological Defects in Two-Dimensional Crystals. (arXiv:2310.05094v1 [cond-mat.soft])**

Federico Ghimenti, Misaki Ozawa, Giulio Biroli, Gilles Tarjus

**Pulsed-mode metalorganic vapor-phase epitaxy of GaN on graphene-coated c-sapphire for freestanding GaN thin films. (arXiv:2310.05127v1 [cond-mat.mtrl-sci])**

Seokje Lee, Muhammad S. Abbas, Dongha Yoo, Keundong Lee, Tobiloba G. Fabunmi, Eunsu Lee, Imhwan Kim, Daniel Jang, Sangmin Lee, Jusang Lee, Ki-Tae Park, Changgu Lee, Miyoung Kim, Yun Seog Lee, Celesta S. Chang, Gyu-Chul Yi

**Realization of multiple topological states and topological phase transitions in (4,0) carbon nanotube derivatives. (arXiv:2310.05233v1 [cond-mat.mtrl-sci])**

Yan Gao, Yu Du, Yun-Yun Bai, Weikang Wu, Qiang Wang, Yong Liu, Kai Liu, Zhong-Yi Lu

**Comparison of different thermostats in the Holstein model. (arXiv:2310.05277v1 [cond-mat.stat-mech])**

N. Fialko, M. Olshevets, V.D. Lakhno

**Pressure-driven homogenization of lithium disilicate glasses. (arXiv:2310.05278v1 [cond-mat.mtrl-sci])**

Yasser Bakhouch, Silvio Buchner, Rafael Abel Silveira, Leonardo Resende, Altair Soria Pereira, Abdellatif Hasnaoui, Achraf Atila

**Combining the D3 dispersion correction with the neuroevolution machine-learned potential. (arXiv:2310.05279v1 [cond-mat.mtrl-sci])**

Penghua Ying, Zheyong Fan

**Surface ferromagnetism in rhombohedral heptalayer graphene moire superlattice. (arXiv:2310.05319v1 [cond-mat.mes-hall])**

Wenqiang Zhou, Jing Ding, Jiannan Hua, Le Zhang, Kenji Watanabe, Takashi Taniguchi, Wei Zhu, Shuigang Xu

**The rotating excitons in two-dimensional materials: Valley Zeeman effect and chirality. (arXiv:2310.05335v1 [cond-mat.mes-hall])**

Yu Cui, Xin-Jun Ma, Jia-Pei Deng, Shao-Juan Li, Ran-Bo Yang, Zhi-Qing Li, Zi-Wu Wang

**Quantum anomalous Hall state in a fluorinated 1T-MoSe$_2$ monolayer. (arXiv:2310.05356v1 [cond-mat.mes-hall])**

Zhen Zhang, Zhichao Zhou, Xiaoyu Wang, Huiqian Wang, Xiuling Li, Xiao Li

**Moir\'e Semiconductors on Twisted Bilayer Dice Lattice. (arXiv:2310.05403v1 [cond-mat.mes-hall])**

Di Ma, Yu-Ge Chen, Yue Yu, Xi Luo

**Observation of universal Kibble-Zurek scaling in an atomic Fermi superfluid. (arXiv:2310.05437v1 [cond-mat.quant-gas])**

Kyuhwan Lee, Sol Kim, Taehoon Kim, Yong-il Shin

**Control of valley optical conductivity and topological phases in buckled hexagonal lattice by orientation of in-plane magnetic field. (arXiv:2310.05439v1 [cond-mat.mes-hall])**

Phusit Nualpijit, Bumned Soodchomshom

**Generalized Landauer bound from absolute irreversibility. (arXiv:2310.05449v1 [cond-mat.stat-mech])**

Lorenzo Buffoni, Francesco Coghi, Stefano Gherardini

**Band structures of strained Kagome lattices. (arXiv:2310.05455v1 [cond-mat.mes-hall])**

Luting Xu, Fan Yang

**Observation of Emergent Superconductivity in the Quantum Spin Hall Insulator Ta2Pd3Te5 via Pressure Manipulation. (arXiv:2310.05532v1 [cond-mat.mtrl-sci])**

Hui Yu, Dayu Yan, Zhaopeng Guo, Yizhou Zhou, Xue Yang, Peiling Li, Zhijun Wang, Xiaojun Xiang, Junkai Li, Xiaoli Ma, Rui Zhou, Fang Hong, Yunxiao Wuli, Youguo Shi, Jian-Tao Wang, Xiaohui Yu

**Composition and optical properties of (In,Ga)As nanowires grown by group-III-assisted molecular beam epitaxy. (arXiv:2310.05582v1 [cond-mat.mtrl-sci])**

M Gómez Ruiz, Aron Castro, Jesús Herranz, Alessandra da Silva, Achim Trampert, Oliver Brandt, Lutz Geelhaar, Jonas Lähnemann

**Mode-Shell correspondence, a unifying theory in topological physics -- Part I: Chiral number of zero-modes. (arXiv:2310.05656v1 [cond-mat.mes-hall])**

Lucien Jezequel, Pierre Delplace

**Quasi van der Waals Epitaxy of Rhombohedral-stacked Bilayer WSe2 on GaP(111) Heterostructure. (arXiv:2310.05660v1 [cond-mat.mes-hall])**

Aymen Mahmoudi, Meryem Bouaziz, Niels Chapuis, Geoffroy Kremer, Julien Chaste, Davide Romanin, Marco Pala, François Bertran, Patrick Le Fèvre, Iann C. Gerber, Gilles Patriarche, Fabrice Oehler, Xavier Wallart, Abdelkarim Ouerghi

**Secondary proximity effect in a side-coupled double quantum dot structure. (arXiv:2310.05663v1 [cond-mat.mes-hall])**

Jia-Ning Wang, Yong-Chen Xiong, Wang-Huai Zhou, Tan Peng, Ziyu Wang

**Interplay of valley, layer and band topology towards interacting quantum phases in bilayer graphene moire superlattice. (arXiv:2310.05667v1 [cond-mat.mes-hall])**

Yungi Jeong, Hangyeol Park, Taeho Kim, K. Watanabe, T. Taniguchi, Jeil Jung, Joonho Jang

**Visualizing delocalized quasiparticles in the vortex state of NbSe$_2$. (arXiv:2310.05716v1 [cond-mat.supr-con])**

Jian-Feng Ge, Koen M. Bastiaans, Jiasen Niu, Tjerk Benschop, Maialen Ortego Larrazabal, Milan P. Allan

**Desalination Performance of Nano porous Mos$_2$ Membrane on Different Salts of Saline Water: A Molecular Dynamics Study. (arXiv:2310.05729v1 [cond-mat.soft])**

A K M Monjur Morshed, Nudrat Nawal, Md Rashed Nizam, Priom Das

**Stability of fractional Chern insulators with a non-Landau level continuum limit. (arXiv:2310.05758v1 [cond-mat.str-el])**

Bartholomew Andrews, Mathi Raja, Nimit Mishra, Michael Zaletel, Rahul Roy

**2+1D symmetry-topological-order from local symmetric operators in 1+1D. (arXiv:2310.05790v1 [cond-mat.str-el])**

Kansei Inamura, Xiao-Gang Wen

**Controlling Topology through Targeted Symmetry Manipulation in Magnetic Systems. (arXiv:2310.05896v1 [cond-mat.mes-hall])**

Ilyoun Na, Marc Vila, Sinéad M. Griffin

**Protected Fermionic Zero Modes in Periodic Gauge Fields. (arXiv:2310.05913v1 [cond-mat.mes-hall])**

Vo Tien Phong, Eugene J. Mele

**When Superconductivity Crosses Over: From BCS to BEC. (arXiv:2208.01774v4 [cond-mat.supr-con] UPDATED)**

Qijin Chen, Zhiqiang Wang, Rufus Boyack, Shuolong Yang, K. Levin

**Limits of the phonon quasi-particle picture at the cubic-to-tetragonal phase transition in halide perovskites. (arXiv:2211.08197v2 [cond-mat.mtrl-sci] UPDATED)**

Erik Fransson, Petter Rosander, Fredrik Eriksson, J. Magnus Rahm, Terumasa Tadano, Paul Erhart

**Moir\'e Superstructures in Marginally-Twisted NbSe$_2$ Bilayers. (arXiv:2212.06728v3 [cond-mat.mes-hall] UPDATED)**

J. G. McHugh, V. V. Enaldiev, V.I. Fal'ko

**Tuning quantum paramagnetism and d-wave superconductivity in single-layer iron chalcogenides by chemical pressure. (arXiv:2212.13603v2 [cond-mat.supr-con] UPDATED)**

Qiang Zou, Basu Dev Oli, Huimin Zhang, Tatsuya Shishidou, Daniel Agterberg, Michael Weinert, Lian Li

**Enhancement of Second-Order Non-Hermitian Skin Effect by Magnetic Fields. (arXiv:2212.14691v2 [cond-mat.mes-hall] UPDATED)**

Chang-An Li, Björn Trauzettel, Titus Neupert, Song-Bo Zhang

**Dynamics of Rapidly Rotating Bose-Einstein Quantum Droplets. (arXiv:2302.07481v3 [cond-mat.quant-gas] UPDATED)**

Szu-Cheng Cheng, Yu-Wen Wang, Wen-Hsuan Kuan

**Complex semiclassical theory for non-Hermitian quantum systems. (arXiv:2303.01525v3 [cond-mat.mes-hall] UPDATED)**

Guang Yang, Yongkang Li, Yongxu Fu, Zhenduo Wang, Yi Zhang

**Experimental evidence for Berry curvature multipoles in antiferromagnets. (arXiv:2303.03274v3 [cond-mat.mes-hall] UPDATED)**

Soumya Sankar, Ruizi Liu, Xue-Jian Gao, Qi-Fang Li, Caiyun Chen, Cheng-Ping Zhang, Jiangchang Zheng, Yi-Hsin Lin, Kun Qian, Ruo-Peng Yu, Xu Zhang, Zi Yang Meng, Kam Tuen Law, Qiming Shao, Berthold Jäck

**Entanglement Resolution with Respect to Conformal Symmetry. (arXiv:2303.07724v2 [hep-th] UPDATED)**

Christian Northe

**Opacity of graphene independent of light frequency and polarization due to the topological charge of the Dirac points. (arXiv:2303.14549v2 [cond-mat.mes-hall] UPDATED)**

Matheus S. M. de Sousa, Wei Chen

**Tuning the lattice thermal conductivity in van-der-Waals structures through rotational (dis)ordering. (arXiv:2304.06978v2 [cond-mat.mtrl-sci] UPDATED)**

Fredrik Eriksson, Erik Fransson, Christopher Linderälv, Zheyong Fan, Paul Erhart

**Efficient GW calculations via the interpolation of the screened interaction in momentum and frequency space: The case of graphene. (arXiv:2304.10810v2 [cond-mat.mtrl-sci] UPDATED)**

Alberto Guandalini, Dario A. Leon, Pino D'Amico, Claudia Cardoso, Andrea Ferretti, Massimo Rontani, Daniele Varsano

**Dynamics of parafermionic states in transport measurements. (arXiv:2305.08906v2 [cond-mat.mes-hall] UPDATED)**

Ida E. Nielsen, Jens Schulenborg, Reinhold Egger, Michele Burrello

**Foldy-Wouthuysen transformation and multiwave states of a graphene electron in external fields and free (2+1)-space. (arXiv:2305.11879v2 [cond-mat.mes-hall] UPDATED)**

Alexander J. Silenko

**Modeling of experimentally observed topological defects inside bulk polycrystals. (arXiv:2305.16454v2 [cond-mat.mtrl-sci] UPDATED)**

Siddharth Singh, He Liu, Rajat Arora, Robert M. Suter, Amit Acharya

**Average Symmetry Protected Higher-order Topological Amorphous Insulators. (arXiv:2306.02246v2 [cond-mat.dis-nn] UPDATED)**

Yu-Liang Tao, Jiong-Hao Wang, Yong Xu

**Flat bands and magnetism in $\mathrm{\mathbf{Fe_4 Ge Te_2}}$ and $\mathrm{\mathbf{Fe_5GeTe_2}}$ due to bipartite crystal lattices. (arXiv:2306.15996v3 [cond-mat.mtrl-sci] UPDATED)**

Fuyi Wang, Haijun Zhang

**Scaling of entanglement entropy at quantum critical points in random spin chains. (arXiv:2307.00062v2 [cond-mat.dis-nn] UPDATED)**

Prashant Kumar, R. N. Bhatt

**Bilayer Kagome Borophene with Multiple van Hove Singularities. (arXiv:2307.07137v2 [cond-mat.mtrl-sci] UPDATED)**

Qian Gao, Qimin Yan, Zhenpeng Hu, Lan Chen

**Chiral topological whispering gallery modes formed by gyromagnetic photonic crystals. (arXiv:2307.12495v2 [physics.optics] UPDATED)**

Yongqi Chen, Nan Gao, Guodong Zhu, Yurui Fang

**Unconventional optical response in monolayer graphene upon dominant intraband scattering. (arXiv:2307.15945v3 [cond-mat.mes-hall] UPDATED)**

Palash Saha, Bala Murali Krishna Mariserla

**Probing the fractional quantum Hall phases in valley-layer locked bilayer MoS$_{2}$. (arXiv:2308.02821v2 [cond-mat.mes-hall] UPDATED)**

Siwen Zhao, Jinqiang Huang, Valentin Crépel, Xingguang Wu, Tongyao Zhang, Hanwen Wang, Xiangyan Han, Zhengyu Li, Chuanying Xi, Senyang Pan, Zhaosheng Wang, Kenji Watanabe, Takashi Taniguchi, Benjamin Sacépé, Jing Zhang, Ning Wang, Jianming Lu, Nicolas Regnault, Zheng Vitto Han

**Non-Abelian Fibonacci quantum Hall states in 4-layer rhombohedral stacked graphene. (arXiv:2308.09702v2 [cond-mat.mes-hall] UPDATED)**

Abigail Timmel, Xiao-Gang Wen

**Vortex structure and spectrum of atomic Fermi superfluid in a spherical bubble trap. (arXiv:2308.10065v2 [cond-mat.quant-gas] UPDATED)**

Yan He, Chih-Chun Chien

**Direct measurement of photoinduced transient conducting state in multilayer 2H-MoTe2. (arXiv:2308.16840v2 [cond-mat.mes-hall] UPDATED)**

XinYu Zhou, H Wang, Q M Liu, S J Zhang, S X Xu, Q Wu, R S Li, L Yue, T C Hu, J Y Yuan, S S Han, T Dong, D Wu, N L Wang

**Fractional quantum Hall states with variational Projected Entangled-Pair States: a study of the bosonic Harper-Hofstadter model. (arXiv:2309.12811v2 [cond-mat.str-el] UPDATED)**

Erik Lennart Weerda, Matteo Rizzi

Found 8 papers in prb Kirigami, the ancient technique of paper cutting, has been successfully applied to enhance the stretchability and ductility of nanoscale graphene. However, existing experimentally realized graphene kirigami (GK) are created by introducing parallel cuts, exhibiting exceptional mechanical properties i… Recently, vacancy-induced ferromagnetism in nanostructured materials, that in the pristine state are diamagnetic, aroused great interest among researchers due to their strong potential for the development of new technologies. In particular, vacancy-induced ferromagnetism is persistent at high temper… Schwinger boson mean-field theory is a powerful approach to study frustrated magnetic systems, which allows to distinguish long-range magnetic orders from quantum spin liquid phases, where quantum fluctuations remain strong up to zero temperature. In this paper, we use this framework to study the He… Despite recent intensive research on topological aspects of open quantum systems, effects of strong interactions have not been sufficiently explored. In this paper, we demonstrate that complex-valued interactions induce the Liouvillian skin effect by analyzing a one-dimensional correlated model with… The formation of persistent charge currents in mesoscopic systems remains an interesting and actual topic of condensed matter research. Here, we analyze the formation of spontaneous arising persistent currents of charged fermions in two-dimensional electron-hole ribbons on the top and bottom of a th… The opacity of graphene is known to be approximately given by the fine-structure constant $α$ times $π$. We point out the fact that the opacity is roughly independent of the frequency and polarization of the light can be attributed to the topological charge of the Dirac points. As a result, one can … The recent experimental claim of room-temperature ambient-pressure superconductivity in a Cu-doped lead- apatite (LK-99) has ignited substantial research interest in both experimental and theoretical domains. Previous density functional theory (DFT) calculations with the inclusion of an on-site Hubb… We demonstrate the existence and propagation of three hybrid modes of surface plasmon polaritons supported by two graphene monolayers coating a solid film. These modes propagate long distances with short wavelengths, which are suitable features to enhance the heat conduction along the film interface…

Date of feed: Tue, 10 Oct 2023 03:17:01 GMT**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **Deformation response of highly stretchable and ductile graphene kirigami under uniaxial and biaxial tension**

Pan Shi, Yao Chen, Ye Wei, Jian Feng, Tong Guo, Yongming Tu, and Pooya Sareh

Author(s): Pan Shi, Yao Chen, Ye Wei, Jian Feng, Tong Guo, Yongming Tu, and Pooya Sareh

[Phys. Rev. B 108, 134105] Published Mon Oct 09, 2023

**High-temperature vacancy-induced magnetism in nanostructured materials**

D. H. Mosca, J. Varalda, and C. A. Dartora

Author(s): D. H. Mosca, J. Varalda, and C. A. Dartora

[Phys. Rev. B 108, 134410] Published Mon Oct 09, 2023

**Schwinger boson study of the ${J}_{1}\text{−}{J}_{2}\text{−}{J}_{3}$ kagome Heisenberg antiferromagnet with Dzyaloshinskii-Moriya interactions**

Dario Rossi, Johannes Motruk, Louk Rademaker, and Dmitry A. Abanin

Author(s): Dario Rossi, Johannes Motruk, Louk Rademaker, and Dmitry A. Abanin

[Phys. Rev. B 108, 144406] Published Mon Oct 09, 2023

**Interaction-induced Liouvillian skin effect in a fermionic chain with a two-body loss**

Shu Hamanaka, Kazuki Yamamoto, and Tsuneya Yoshida

Author(s): Shu Hamanaka, Kazuki Yamamoto, and Tsuneya Yoshida

[Phys. Rev. B 108, 155114] Published Mon Oct 09, 2023

**Persistent current-carrying state of charge quasiparticles in an $np$ ribbon featuring a single Dirac cone**

Anatoly M. Kadigrobov and Ilya M. Eremin

Author(s): Anatoly M. Kadigrobov and Ilya M. Eremin

[Phys. Rev. B 108, 155407] Published Mon Oct 09, 2023

**Opacity of graphene independent of light frequency and polarization due to the topological charge of the Dirac points**

Matheus S. M. de Sousa and Wei Chen

Author(s): Matheus S. M. de Sousa and Wei Chen

[Phys. Rev. B 108, 165201] Published Mon Oct 09, 2023

**Symmetry breaking induced insulating electronic state in ${\mathrm{Pb}}_{9}\mathrm{Cu}{({\mathrm{PO}}_{4})}_{6}\mathrm{O}$**

Jiaxi Liu, Tianye Yu, Jiangxu Li, Jiantao Wang, Junwen Lai, Yan Sun, Xing-Qiu Chen, and Peitao Liu

Author(s): Jiaxi Liu, Tianye Yu, Jiangxu Li, Jiantao Wang, Junwen Lai, Yan Sun, Xing-Qiu Chen, and Peitao Liu

[Phys. Rev. B 108, L161101] Published Mon Oct 09, 2023

**Long-range, short-wavelength, and ultrafast heat conduction driven by three plasmon modes supported by graphene**

Jose Ordonez-Miranda, Yuriy A. Kosevich, Masahiro Nomura, and Sebastian Volz

Author(s): Jose Ordonez-Miranda, Yuriy A. Kosevich, Masahiro Nomura, and Sebastian Volz

[Phys. Rev. B 108, L161404] Published Mon Oct 09, 2023

Found 1 papers in prl Machine learning-assisted metadynamics is used to study water autoionization, one of the most important properties of water for all biological and chemical process including electrolysis (related to batteries).

Date of feed: Tue, 10 Oct 2023 03:16:59 GMT**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **Mechanistic Insights into Water Autoionization through Metadynamics Simulation Enhanced by Machine Learning**

Ling Liu, Yingqi Tian, Xuanye Yang, and Chungen Liu

Author(s): Ling Liu, Yingqi Tian, Xuanye Yang, and Chungen Liu

[Phys. Rev. Lett. 131, 158001] Published Mon Oct 09, 2023

Found 2 papers in pr_res Particle formation represents a central theme in various branches of physics, often associated to confinement. Here we show that dynamical hadron formation can be spectroscopically detected in an ultracold atomic setting within the most paradigmatic and simplest model of condensed matter physics, th… Wires made of topological insulators (TI) are a promising platform for searching for Majorana bound states. These states can be probed by analyzing the fractional ac Josephson effect in Josephson junctions with the TI wire as a weak link. An axial magnetic field can be used to tune the system from t…

Date of feed: Tue, 10 Oct 2023 03:17:01 GMT**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **Spectroscopic evidence for engineered hadronic bound state formation in repulsive fermionic $\text{SU}(N)$ Hubbard systems**

Miklós Antal Werner, Cătălin Paşcu Moca, Márton Kormos, Örs Legeza, Balázs Dóra, and Gergely Zaránd

Author(s): Miklós Antal Werner, Cătălin Paşcu Moca, Márton Kormos, Örs Legeza, Balázs Dóra, and Gergely Zaránd

[Phys. Rev. Research 5, 043020] Published Mon Oct 09, 2023

**Supercurrent interference in HgTe-wire Josephson junctions**

Wolfgang Himmler, Ralf Fischer, Michael Barth, Jacob Fuchs, Dmitriy A. Kozlov, Nikolay N. Mikhailov, Sergey A. Dvoretsky, Christoph Strunk, Cosimo Gorini, Klaus Richter, and Dieter Weiss

Author(s): Wolfgang Himmler, Ralf Fischer, Michael Barth, Jacob Fuchs, Dmitriy A. Kozlov, Nikolay N. Mikhailov, Sergey A. Dvoretsky, Christoph Strunk, Cosimo Gorini, Klaus Richter, and Dieter Weiss

[Phys. Rev. Research 5, 043021] Published Mon Oct 09, 2023

Found 2 papers in nano-lett

Date of feed: Mon, 09 Oct 2023 13:11:50 GMT**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **[ASAP] Symmetry Engineering in Twisted Bilayer WTe2**

Yijin Zhang, Keisuke Kamiya, Takato Yamamoto, Masato Sakano, Xiaohan Yang, Satoru Masubuchi, Shota Okazaki, Keisuke Shinokita, Tongmin Chen, Kohei Aso, Yukiko Yamada-Takamura, Yoshifumi Oshima, Kenji Watanabe, Takashi Taniguchi, Kazunari Matsuda, Takao Sasagawa, Kyoko Ishizaka, and Tomoki MachidaNano LettersDOI: 10.1021/acs.nanolett.3c02327

**[ASAP] Submillimeter-Long WS2 Nanotubes: The Pathway to Inorganic Buckypaper**

Vojtěch Kundrát, Rita Rosentsveig, Kristýna Bukvišová, Daniel Citterberg, Miroslav Kolíbal, Shachar Keren, Iddo Pinkas, Omer Yaffe, Alla Zak, and Reshef TenneNano LettersDOI: 10.1021/acs.nanolett.3c02783

Found 3 papers in nat-comm **Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **Porphene and porphite as porphyrin analogs of graphene and graphite**

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**Electronic Janus lattice and kagome-like bands in coloring-triangular MoTe2 monolayers**

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**Electrostatic force promoted intermolecular stacking of polymer donors toward 19.4% efficiency binary organic solar cells**

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