Found 61 papers in cond-mat Particle-particle interaction provides a new degree of freedom to induce
novel topological phenomena. Here, we propose to use spatiotemporal modulation
of interaction to realize topological pumping without single-particle
counterpart. Because the modulation breaks time-reversal symmetry, the
multiparticle energy bands of bound states have none-zero Chern number, and
support topological bound edge states. In a Thouless pump, a bound state that
uniformly occupies a topological energy band can be shifted by integer unit
cells per cycle, consistent with the corresponding Chern number. We can also
realize topological pumping of bound edge state from one end to another. The
entanglement entropy between particles rapidly increases at transition points,
which is related to the spatial spread of a bounded pair. In addition, we
propose to realize hybridized pumping with fractional displacement per cycle by
adding an extra tilt potential to separate topological pumping of the bound
state and Bloch oscillations of single particle. Our work could trigger further
studies of correlated topological phenomena that do not have a single-particle
counterpart.
The deep connection among braids, knots and topological physics has provided
valuable insights into studying topological states in various physical systems.
However, identifying distinct braid groups and knot topology embedded in
non-Hermitian systems is challenging and requires significant efforts. Here, we
demonstrate that an unsupervised learning with the representation basis of
$su(n)$ Lie algebra on $n$-fold extended non-Hermitian bands can fully classify
braid group and knot topology therein, without requiring any prior mathematical
knowledge or any pre-defined topological invariants. We demonstrate that the
approach successfully identifies different topological elements, such as
unlink, unknot, Hopf link, Solomon ring, trefoil, and so on, by employing
generalized Gell-Mann matrices in non-Hermitian models with $n$=2 and $n$=3
energy bands. Moreover, since eigenstate information of non-Hermitian bands is
incorporated in addition to eigenvalues, the approach distinguishes the
different parity-time symmetry and breaking phases, recognizes the opposite
chirality of braids and knots, and identifies out distinct topological phases
that were overlooked before. Our study shows significant potential of machine
learning in classification of knots, braid groups, and non-Hermitian
topological phases.
The proposed $\mathcal{A}$ phase and the corresponding trial wavefunction
proposed by Das \emph{et al.} (PRL 131, 056202, 2023) for 5/2 state are argued
to describe the fractional quantum Hall liquid state rather than a phase
separated or stripe or bubble state.
Exceptional points of order $n$ (EP$n$s) appear in non-Hermitian systems as
points where the eigenvalues and eigenvectors coalesce. Whereas EP2s
generically appear in two dimensions (2D), higher-order EPs require a
higher-dimensional parameter space to emerge. In this work, we provide a
complete characterization the appearance of symmetry-induced higher-order EPs
in 2D parameter space. We find that besides EP2s only EP3s, EP4s, and EP5s can
be stabilized in 2D. Moreover, these higher-order EPs must always appear in
pairs with their dispersion determined by the symmetries. Upon studying the
complex spectral structure around these EPs, we find that depending on the
symmetry, EP3s are accompanied by EP2 arcs, and 2- and 3-level open Fermi
structures. Similarly, EP4s and closely related EP5s, which arise due to
multiple symmetries, are accompanied by exotic EP arcs and open Fermi
structures. For each case, we provide an explicit example. We also comment on
the topological charge of these EPs, and discuss similarities and differences
between symmetry-protected higher-order EPs and EP2s.
In this comment, we showed that the Dirac equation in the screw dislocation
space-time also carries a term that represents the torsion of such topological
defect, given by $K_\mu$. Therefore, the Dirac equation worked by Wang et al.
is incomplete since such a term was ignored in your equation (what cannot
happen). In other words, it is only possible to work with the Dirac equation in
the form presented by Wang et al. if the space-time is torsion-free, which is
obviously not the case.
Emergent collective modes in lattices give birth to many intriguing physical
phenomena in condensed matter physics. Among these collective modes, large-area
modes typically feature small level spacings, whilst a single mode tends to be
spatially tightly confined. Here, we theoretically propose and experimentally
demonstrate a unique scale-invariant, large-area, and single-mode topological
cavity mode in a two-dimensional photonic crystal. This mode emerges from the
hybridization of the large-area fundamental Dirac mode and in-gap topological
corner modes. Remarkably, we find that the scale-invariant, large-area, and
single-mode topological cavity mode possesses unique chiralities and with a
tunable mode area under the change of the mass term of the inner topological
nontrivial lattice. We experimentally observe such topological cavity modes in
a 2D photonic system and demonstrate the robustness by introducing disorders in
the cavity structure. Our findings have propelled the forefront of higher-order
topology research, transitioning it from single-lattice systems to
multi-lattice systems and may support promising potential applications,
particularly in vertical-cavity surface-emitting lasers.
We construct an observable mixed state topological order parameter for
symmetry-protected free fermion matter. It resolves the entire table of
topological insulators and superconductors, relying exclusively on the symmetry
class, but not on unitary symmetries. It provides a robust, quantized signal
not only for pure ground states, but also for mixed states in- or out of
thermal equilibrium. Key ingredient is a unitary probe operator, whose phase
can be related to spectral asymmetry, in turn revealing the topological
properties of the underlying state. This is demonstrated analytically in the
continuum limit, and validated numerically on the lattice. The order parameter
is experimentally accessible via either interferometry or full counting
statistics, for example, in cold atom experiments.
The capability of magnons to hybridize and strongly couple with diverse
excitations offers a promising avenue for realizing and controlling emergent
properties that hold significant potential for applications in devices,
circuits, and information processing. In this letter, we present recent
theoretical and experimental developments in magnon-based hybrid systems,
focusing on the combination of magnon excitation in an antiferromagnet with
other excitations, namely plasmons in a topological insulator, phonons in a 2D
AFM, and photons. The existence of THz frequency magnons, plasmons, and phonons
makes magnon-based hybrid systems particularly appealing for
high-operating-speed devices. In this context, we explore several directions to
advance magnon hybrid systems, including strong coupling between a surface
plasmon and magnon polariton in a TI/AFM bilayer, a giant spin Nernst effect
induced by magnon phonon coupling in 2D AFMs, and control of magnon-photon
coupling using spin torque.
We argue that the unusual properties of a wide class of materials based on
Jahn-Teller 3d and 4d ions with different crystal and electronic structures,
from quasi-two-dimensional unconventional superconductors (cuprates,
nickelates, ferropnictides/chalcogenides, ruthenate SrRuO4), manganites with
local superconductivity to 3D ferrates (CaSr)FeO3, nickelates RNiO3 and silver
oxide AgO with unusual charge and magnetic order can be explained within a
single scenario. The properties of these materials are related to the
instability of their highly symmetric Jahn-Teller "progenitors" with the ground
orbital E-state to charge transfer with anti-Jahn-Teller disproportionation and
the formation of a system of effective local composite spin-singlet or
spin-triplet, electronic or hole bosons moving in a non-magnetic or magnetic
lattice. These unusual systems are characterized by an extremely rich variety
of phase states from non-magnetic and magnetic insulators to unusual metallic
and superconducting states.
Optical properties in van der Waals heterostructures based on monolayer
transition-metal dichalcogenides (TMDs), are often dominated by excitonic
transitions. While intrinsic spin-orbit coupling (SOC) and an isotropic band
structure are typically studied in TMDs, in their heterostructures Rashba SOC
and trigonal warping (TW), resulting in bands with threefold anisotropy, are
also present. By considering a low-energy effective Hamiltonian and
Bethe-Salpeter equation, we study the effect of Rashba SOC and TW on the band
structure and absorption spectra. Rashba SOC is predicted to lead to emergent
excitons, which are identified as an admixture between 1s and 2p symmetries. In
contrast, for experimentally relevant values, TW has only a negligible effect
on the absorption spectrum. These findings could guide experimental
demonstrations of emergent bright excitons and further studies of the proximity
effects in van der Waals heterostructure.
We have investigated the structural, elastic, electronic, thermophysical,
superconducting, and optical properties of ScYH6 under uniform hydrostatic
pressures up to 25 GPa, using the density functional theory (DFT) formalism.
Most of results reported here are novel. The compound ScYH6 has been found to
be elastically and thermodynamically stable within the pressure range
considered. The compound is brittle; the brittleness decreases with increasing
pressure. The elastic anisotropy is low and the machinability index is moderate
which increases gradually with rising pressure. The compound is a hard
material. The electronic band structure shows weakly metallic character with
low density of states at the Fermi level. The Debye temperature of the compound
is high and increases with increasing pressure. The Gr\"uneisen parameter of
ScYH6 is low and the phonon thermal conductivity is high at room temperature.
The compound is a very efficient reflector of infrared radiation. The compound
is also an efficient absorber of visible and ultraviolet light. The overall
effect of pressure on optical parameters is small. We have also investigated
the pressure induced changes in the predicted superconducting state properties
by considering the changes in the electronic density of states at the Fermi
level, Debye temperature, and the repulsive Coulomb pseudopotential. The
superconducting transition temperature is found to increase gradually with
increasing pressure.
We theoretically study valley-filtering in pristine graphene irradiated by
bicircular counter-rotating laser drive. The dynamical symmetry of the graphene
and laser drive disrupts graphene's inversion symmetry, which results distinct
quasi-energy states and Floquet band occupations in the two valleys.
Controlling the relative phase between the bicircular laser drive ultimately
allows to blocks the contribution from one valley while allowing the opposite
valley currents in the system. For practical realization of valley-based
device, we propose configurational setup for valley filters and valley valve
consisting of two graphene nanoribbons irradiated by two bicircular
counter-rotating laser drives with a relative phase shift. It is observed that
the relative phase between the two bicircular laser drives offer a control knob
to generate valley-selective currents and transport responses with very high
efficiency by an all-optical way. In addition, our findings about valley filter
and valley valve are robust against moderate disorder and modest changes in
driving laser parameters. Present work opens an avenue to realise light-based
valleytronics devices in reality.
In the ultra-thin regime, Bi2Te3 films feature two surfaces (with each
surface being a two-dimensional Dirac-fermion system) with complicated spin
textures and a tunneling term between them. We find in this regime that the
quasiparticle scattering is completely different compared with the thick-film
case and even behaves differently at each thickness. The thickness-dependent
warping effect and tunneling term are found to be the two main factors that
govern the scattering behaviors. The inter-band back-scattering that signals
the existence of a tunneling term is found to disappear at 4 quintuple layers
by the step-edge reflection approach. A four-band model is presented that
captures the main features of the thickness-dependent scattering behaviors. Our
work clarifies that the prohibition of back-scattering guaranteed by symmetry
in topological insulators breaks down in the ultra-thin regime.
The topological magnetoelectric effect (TME) is a unique macroscopic
manifestation of quantum states of matter possessing topological order and it
is described by axion electrodynamics. In three-dimensional topological
insulators, for instance, the axion coupling is of the order of the fine
structure constant, and hence a perturbative analysis of the field equations is
plenty justified. In this paper we use Green's function techniques to obtain
time-dependent solutions to the axion field equations in the presence of a
planar domain-wall separating two media with different topological order. We
apply our results to investigate the radiation of a short linear antenna near
the domain-wall.
This is the text of my report presented at the 29th Solvay Conference on
Physics on `The Structure and Dynamics of Disordered Systems' held in Bruxelles
from October 19 to 21, 2023. I consider the problem of minimizing a random
energy function $H(\sigma)$, where $\sigma$ is an $N$-dimensional vector, in
the high-dimensional regime $N\gg 1$. Using as a reference point a 1986 paper
by Fu and Anderson, I take stock of the progress on this question over the last
40 years. In particular, I focus on the influence and ramifications of ideas
originating from statistical physics. My own conclusion is that several of the
most fundamental questions in this area (which in 1986 were barely formulated)
have now received mathematically rigorous answers, at least in simple -- yet
highly nontrivial -- settings. Instrumental to this spectacular progress was
the dialogue between different research communities: physics, computer science,
mathematics.
In this study, ultrafast optical spectroscopy was employed to elucidate the
intricate topological features of EuIn$_2$As$_2$, a promising candidate for a
magnetic topological-crystalline axion insulator. Our investigation, focusing
on the real-time evolution of topological states, unveiled a narrow surface
magnetic gap (2$\Delta_0$ $\simeq$ 8.2 meV)) emerging at the antiferromagnetic
transition temperature ($T_N$ $\approx$ 16 K). Below $T_N$, two extremely
low-energy collective modes, $\omega_1$ and $\omega_2$, with frequencies of
$\sim$9.9 and 21.6 GHz at $T$ = 4 K, respectively, were observed, exhibiting
strong temperature dependence. $\omega_1$ correlates with an acoustic phonon,
while $\omega_2$ is associated with a magnon. The results suggest that
EuIn$_2$As$_2$ has the potential to manifest a magnetic topological-crystalline
axion insulator, presenting a small magnetic energy gap on the (001) surface.
The findings further our understanding of the interplay between magnetism and
topology in this material, showcasing its potential for applications in quantum
information processing and spintronics.
Machine learned potentials (MLPs) have been widely employed in molecular
dynamics (MD) simulations to study thermal transport. However, literature
results indicate that MLPs generally underestimate the lattice thermal
conductivity (LTC) of typical solids. Here, we quantitatively analyze this
underestimation in the context of the neuroevolution potential (NEP), which is
a representative MLP that balances efficiency and accuracy. Taking crystalline
silicon, GaAs, graphene, and PbTe as examples, we reveal that the fitting
errors in the machine-learned forces against the reference ones are responsible
for the underestimated LTC as they constitute external perturbations to the
interatomic forces. Since the force errors of a NEP model and the random forces
in the Langevin thermostat both follow a Gaussian distribution, we propose an
approach to correcting the LTC by intentionally introducing different levels of
force noises via the Langevin thermostat and then extrapolating to the limit of
zero force error. Excellent agreement with experiments is obtained by using
this correction for all the prototypical materials over a wide range of
temperatures. Based on spectral analyses, we find that the LTC underestimation
mainly arises from increased phonon scatterings in the low-frequency region
caused by the random force errors.
It is widely believed that the origin of a significant cause for the voltage
and capacity fading observed in lithium (Li)-ion batteries is related to
structural modifications occurring in the cathode material during the Li-ion
insertion/de-insertion process. The Li-ion insertion/de-insertion mechanism and
the resulting structural changes are known to exert a severe strain on the
lattice, and consequently leading to performance degradation. Here, with a view
to shed more light on the effect of such strain on the structural properties of
the cathode material, we have systematically investigated the pressure
dependence of structural and transport properties of an LixCoO2 single crystal,
grown using 5% excess Li in the precursors. Ambient pressure synchrotron
diffraction on these crystals reveals that, the excess Li during the growth,
has facilitated the stabilization of a layered rhombohedral phase (space group
R3m) as well as a disordered rock-salt phase (space group Fm3m). The volume
fraction of the rhombohedral and cubic phase is 60:40, respectively, which
remains unchanged up to 10.6 GPa. No structural phase transition has been
observed up to 10.6 GPa. An increase in resistance with a decrease in
temperature has revealed the semi-metallic nature of the sample. Further, the
application of hydrostatic pressure up to 2.8 GPa shows the enhancement of
semi-metallic nature. The obtained experimental results can be qualitatively
explained via density functional theory (DFT) and thermodynamics modelling. The
calculated density of states was reduced, and the activation energy was
increased by applied pressure. Our investigations indicate a significant phase
stability of the mixed phase crystals under externally applied high pressure
and thus suggest the possible use of such mixed phase materials as a cathode in
lithium-ion batteries.
In this study, we investigate intrinsic magnetic topological insulator
MnBi2Te4 thin films grown by molecular beam epitaxy. We observe a reentrant
quantum anomalous Hall effect when the Fermi energy enters the valance band and
magnetic field equals zero, indicating the emergence of the Chern Anderson
insulator state. The discovery opens a new avenue for realizing the QAH effect
and underscores the fundamental role of both Berry curvature and Anderson
localization.
We study topological states of matter in quasicrystals, which do not rely on
crystalline orders. In the absence of a bandstructure description and
spin-orbit coupling, we show that a three-dimensional quasicrystal can
nevertheless form a topological insulator. It relies on a combination of
noncrystallographic rotational symmetry of quasicrystals and electronic orbital
space symmetry, which is the quasicrystalline counterpart of topological
crystalline insulator. The resulting topological state obeys a non-trivial
twisted bulk-boundary correspondence and lacks a good metallic surface. The
topological surface states, localized on the top and bottom planes respecting
the quasicrystalline symmetry, exhibit a new kind of multifractality with
probability density concentrates mostly on high symmetry patches. They form a
near-degenerate manifold of 'immobile' states whose number scales
proportionally with the macroscopic sample size. This can open the door to a
novel platform for topological surface physics distinct from the crystalline
counterpart.
Obeying non-Abelian statistics, Majorana fermion holds a promise to implement
topological quantum computing. It was found that Majorana fermion can be
simulated by the zero-energy excitation in a semiconducting nanowire with
strong spin-orbit coupling interacting with a $s$-wave superconductor under a
magnetic field. We here propose an alternative scheme to simulate the Majorana
fermion in a trapped-ion system. Our dimitrized-ion configuration permits us to
generate the Majorana modes not only at zero energy but also at the nonzero
ones. We also investigate the controllability of the Majorana modes by Floquet
engineering. It is found that a widely tunable number of Majorana modes are
created on demand by applying a periodic driving on a topologically trivial
trapped-ion system. Enriching the platforms for simulating Majorana fermion,
our result would open another avenue for realizing topological quantum
computing.
It is known that the excitations in graphene-like materials in external
electromagnetic field are described by solutions of massless two-dimensional
Dirac equation which includes both Hermitian off-diagonal matrix and scalar
potentials. Up to now, such two-component wave functions were calculated for
different forms of external potentials but, as a rule, depending on one spatial
variable only. Here, we shall find analytically the solutions for a wide class
of combinations of matrix and scalar external potentials which physically
correspond to applied mutually orthogonal magnetic and longitudinal
electrostatic fields, both depending really on two spatial variables. The main
tool for this progress was provided by supersymmetrical (SUSY) intertwining
relations, namely, by their most general - asymmetrical - form proposed
recently by the authors. Such SUSY-like method is applied in two steps
similarly to the second order factorizable (reducible) SUSY transformations in
ordinary Quantum Mechanics.
We present the viewpoint of treating one-dimensional band structures as
Riemann surfaces, linking the unique properties of non-Hermiticity to the
geometry and topology of the Riemann surface. Branch cuts and branch points
play a significant role when this viewpoint is applied to both the
open-boundary spectrum and the braiding structure. An open-boundary spectrum is
interpreted as branch cuts connecting certain branch points, and its
consistency with the monodromy representation severely limits its possible
morphology. A braid word for the Brillouin zone can be read off from its
intersections with branch cuts, and its crossing number is given by the winding
number of the discriminant. These results open new avenues to generate
important insights into the physical behaviors of non-Hermitian systems.
Binary kagome compounds TmXn (T = Mn, Fe, Co; X = Sn, Ge; m:n = 3:1, 3:2,
1:1) have garnered recent interest owing to the presence of both topological
band crossings and flat bands arising from the geometry of the metal-site
kagome lattice. To exploit these electronic features for potential applications
in spintronics, the growth of high quality heterostructures is required. Here
we report the synthesis of Fe/FeSn and Co/FeSn bilayers on Al2O3 substrates
using molecular beam epitaxy to realize heterointerfaces between elemental
ferromagnetic metals and antiferromagnetic kagome metals. Structural
characterization using high-resolution X-ray diffraction, reflection
high-energy electron diffraction, and electron microscopy reveals the FeSn
films are flat and epitaxial. Rutherford backscattering spectroscopy was used
to confirm the stoichiometric window where the FeSn phase is stabilized, while
transport and magnetometry measurements were conducted to verify metallicity
and magnetic ordering in the films. Exchange bias was observed, confirming the
presence of antiferromagnetic order in the FeSn layers, paving the way for
future studies of magnetism in kagome heterostructures and potential
integration of these materials into devices.
We consider a trimer Su-Schrieffer-Heeger (SSH) tight-binding Hamiltonian
keeping up to next-nearest-neighbor (NNN) hopping terms and on-site potential
energy. The Bloch Hamiltonian can be expressed in terms of all the eight
generators (i.e. Gell-Mann matrices) of the SU(3) group. We provide exact
analytical expressions of three dispersive energy bands and the corresponding
eigenstates for any choices of the system parameters. The system lacks full
chiral symmetry since the energy spectrum is not symmetric around zero, except
at isolated Bloch wavevectors. We explore parity, time reversal, and certain
special chiral symmetries for various system parameters. We discuss the
bulk-boundary correspondence by numerically computing the Zak phase for all the
bands and the boundary modes in the open boundary condition. There are three
different kinds of topological phase transitions which are classified based on
the gap closing points in the Brillouin zone (BZ) while tuning the
nearest-neighbor (NN) and NNN hopping terms. We find that quantized changes (in
units of $\pi$) in two out of three Zak phases characterize these topological
phase transitions. We propose another bulk topological invariant, namely the
$\textit{sub-lattice winding number}$, which also characterizes the topological
phase transitions changing from $ \nu^{\alpha} = 0 \leftrightarrow 2 $ and $
\nu^{\alpha} = 0 \leftrightarrow 1 \leftrightarrow 2 $ ($\alpha $: sub-lattice
index). The sub-lattice winding number provides a relatively simple analytical
understanding of topological phases and may help in characterizing topological
phases of systems without chiral symmetry.
Gauging a finite subgroup of a global symmetry can map conventional phases
and phase transitions to unconventional ones. In this work, we study, as a
concrete example, an emergent $\mathbb{Z}_2$-gauged system with global symmetry
$U(1)$, namely, the $\mathbb{Z}_2$-gauged Bose-Hubbard model both in 1-D and in
2-D. In certain limits, there is an emergent mixed 't Hooft anomaly between the
quotient $\tilde{U}(1)$ symmetry and the dual $\hat{\mathbb{Z}}_2$ symmetry. In
1-D, the superfluid phase is mapped to an intrinsically gapless
symmetry-protected topological (SPT) phase, as supported by density-matrix
renormalization group (DMRG) calculations. In 2-D, the original
superfluid-insulator transition becomes a generalized deconfined quantum
critical point (DQCP) between a gapless SPT phase, where a SPT order coexists
with Goldstone modes, and a $\tilde{U}(1)$-symmetry-enriched topological (SET)
phase. We also discuss the stability of these phases and the critical points to
small perturbations and their potential experimental realizations. Our work
demonstrates that partial gauging is a simple and yet powerful approach in
constructing novel phases and quantum criticalities.
While graphene oxide (GO) is representative of a disordered phase of
oxocarbons with lackluster electronic properties, the coexistence of ordered,
stoichiometric solid-state carbon oxides with graphene brings renewed momentum
to the exploration of two-dimensional crystalline oxocarbons. This enduring
subject, spanning decades, has recently witnessed significant advancements. In
this context, our study delves into a novel material class, COF-66, notable for
its meticulously ordered two-dimensional crystalline structure and intrinsic
porosity. Employing a global optimization algorithm alongside
density-functional calculations, our investigation highlights a standout member
within the COF-66 family exceptional quasi-flat oxocarbon (C6O6)exhibiting an
unconventional oxygen-decorated pore configuration. This pioneering study
introduces C6O6 as an innovative entrant into the crystalline carbon oxide
arena, augmenting the established understanding alongside the well-recognized
graphene oxide and two graphene monoxide, i.e. {\alpha}-GMO and \b{eta}-GMO.
Expanding the exploration, the COF-66 series encompasses 2D-porous carbon
nitride (C6N6) and the recently synthesized 2D-porous boroxine (B6O6), adhering
to a generalized stoichiometry of X6Y6, where X = B, C, and Y = B, N, O, with X
6= Y. Remarkably, the entire COF-66 ensemble adopts a 2D-crystalline framework,
with the exception of C6B6, which assumes a distinct 3D-crystalline
arrangement. Employing the PBE (HSE06) level of theory, our electronic
structure calculations yield band gap values of 0.01 (0.05) eV, 3.68 (5.29) eV,
0.00 (0.23) eV, and 1.53 (3.09) eV for B6N6, B6O6, C6B6, and C6N6,
respectively, reinforcing and aligning with prior investigations.
We explore the critical properties of a topological transition in a
two-dimensional, amorphous lattice with randomly distributed points. The model
intrinsically breaks the time-reversal symmetry without an external magnetic
field, akin to a Chern insulator. Here, the topological transition is induced
by varying the density of lattice points or adjusting the mass parameter. Using
the two-terminal conductance and multifractality of the wavefunction, we found
that the topological transition belongs to the same universality class as the
integer quantum Hall transition. Regardless of the approach to the critical
point across the phase boundary, the localization length exponent remains
within $\nu \approx 2.55 - 2.61$. The irrelevant scaling exponent for both the
observables is $y \approx 0.3(1)$, comparable to the values obtained using
transfer matrix analysis in the Chalker-Coddigton network. Additionally, the
investigation of the entire distribution function of the inverse participation
ratio at the critical point shows possible deviations from the parabolic
multifractal spectrum at the anomalous quantum Hall transition.
We report on the coexistence of both normal and topological insulating phases
in InAs/GaSb bilayer quantum well induced by the built-in electric field tuned
optically and electrically. The emergence of topological and normal insulating
phases is assessed based on the evolution of the charge carrier densities, the
resistivity dependence of the gap via in-plane magnetic fields and the thermal
activation of carriers. For the Hall bar device tuned optically, we observe the
fingerprints associated with the presence of only the topological insulating
phase. For another Hall bar processed identically but with an additional top
gate, the coexistence of normal and topological insulating phases is found by
electrical tuning. Our finding paves the way for utilizing a new
electro-optical tuning scheme to manipulate InAs/GaSb bilayer quantum wells to
obtain trivial-topological insulating interfaces in the bulk rather than at the
physical edge of the device.
The role of defects in two-dimensional semiconductors and how they affect the
intrinsic properties of these materials have been a wide researched topic over
the past decades. Optical characterization such as photoluminescence and Raman
spectroscopies are important tools to probe their physical properties and the
impact of defects. However, conventional optical techniques present a spatial
resolution limitation lying in a $\mu$m-scale, which can be overcomed by the
use of near-field optical measurements. Here, we use tip-enhanced
photoluminescence and Raman spectroscopies to unveil nanoscale optical
heterogeneities at grain boundaries, local strain fields and edges in grown
MoS$_{2}$ monolayers. A noticeable enhancement of the exciton peak intensity
corresponding to a trion emission quenching is observed at narrow regions down
to 47 nm of width at grain boundaries related to doping effects. Besides,
localized strain fields inside the sample lead to non-uniformities in the
intensity and energy position of photoluminescence peaks. Finally, distinct
samples present different nano-optical responses at their edges due to strain
and passivation defects. The passivated defective edges show a
photoluminescence intensity enhancement and energy blueshift as well as a
frequency blueshift of the 2LA Raman mode. On the other hand, the strained
edges display a photoluminescence energy redshift and frequency redshifts for
E$_{2g}$ and 2LA Raman modes. Our work shows that different defect features can
be only probed by using optical spectroscopies with a nanometric resolution,
thus revealing hindered local impact of different nanoscale defects in
two-dimensional materials.
Double layer quantum systems are promising platforms for realizing novel
quantum phases. Here, we report a study of quantum oscillations (QOs) in a
weakly coupled double layer system, composed of a large angle twisted double
bilayer graphene (TDBG). We observe two different QOs at low temperature, one
with a periodicity in carrier density (n), i.e. Shubnikov de Haas oscillation
(SdHO) due to Landau quantization, and the other one in displacement field (D),
resulting a grid pattern. We quantify the interlayer coupling strength by
measuring the interlayer capacitance from the grid pattern with a capacitance
model, revealing an electron hole asymmetry. At high temperature when SdHO are
thermal smeared, we observe resistance peaks when LLs from two minivalleys in
the moir\'e Brillion zone are aligned, regardless of carrier density;
eventually, it results in a two fold increase of oscillating frequency in D,
serving as a smoking gun evidence of the magneto intersubband oscillations
(MISO) in a double layer system. The temperature dependence of MISO suggests
electron-electron interaction between two minivalleys play a crucial rule in
the scattering, and the scattering times obtained from MISO thermal damping are
found to be correlated with the interlayer coupling strength. Our study reveals
an intriguing interplay among Landau quantization, moir\'e band structure, and
scatterings.
The multifaceted physics of oxides is shaped by their composition and the
presence of defects, which are often accompanied by the formation of polarons.
The simultaneous presence of polarons and defects, and their complex
interactions, pose challenges for first-principles simulations and experimental
techniques. In this study, we leverage machine learning and a first-principles
database to analyze the distribution of surface oxygen vacancies (V$_{\rm O}$)
and induced small polarons on rutile TiO$_2$(110), effectively disentangling
the interactions between polarons and defects. By combining neural-network
supervised learning and simulated annealing, we elucidate the inhomogeneous
V$_{\rm O}$ distribution observed in scanning probe microscopy (SPM). Our
innovative approach allows us to understand and predict defective surface
patterns at previously inaccessible length scales, identifying the specific
role of individual types of defects. Specifically, surface-polaron-stabilizing
V$_{\rm O}$-configurations are identified, which could have consequences for
surface reactivity.
Boltzmann's constant reflects a historical misunderstanding of the concept of
entropy, whose informational nature is obfuscated when expressed in J/K. We
suggest that the development of temperature and energy, historically prior to
that of entropy, does not amount to their logical priority: Temperature should
be defined in terms of entropy, not vice versa. Following the precepts of
information theory, entropy is measured in bits, and coincides with information
capacity at thermodynamic equilibrium. Consequently, not only is the
temperature of an equilibrated system expressed in J/bit, but it acquires an
operational meaning: It is the cost in energy to increase its information
capacity by 1 bit. Our proposal also supports the notion of available capacity,
analogous to free energy. Finally, it simplifies Landauer's cost and clarifies
that it is a cost of displacement, not of erasure.
Defects dictate the properties of many functional materials. To understand
the behaviour of defects and their impact on physical properties, it is
necessary to identify the most stable defect geometries. However, global
structure searching is computationally challenging for high-throughput defect
studies or materials with complex defect landscapes, like alloys or disordered
solids. Here, we tackle this limitation by harnessing a machine-learning
surrogate model to qualitatively explore the defect structural landscape. By
learning defect motifs in a family of related metal chalcogenide and mixed
anion crystals, the model successfully predicts favourable reconstructions for
unseen defects in unseen compositions for 90% of cases, thereby reducing the
number of first-principles calculations by 73%. Using CdSe$_x$Te$_{1-x}$ alloys
as an exemplar, we train a model on the end member compositions and apply it to
find the stable geometries of all inequivalent vacancies for a range of mixing
concentrations, thus enabling more accurate and faster defect studies for
configurational complex systems.
Spin-orbit torques (SOTs) act as efficient drivers for nanoscale magnetic
systems, such as in magnetic tunnel junctions, nano-oscillators and racetrack
geometries. In particular, in combination with materials exhibiting high
Dzyaloshinskii--Moriya interaction, SOTs are considered to result in
well-controlled deterministic magnetisation dynamics and are, therefore, used
as robust drives to move and create magnetic skyrmions. In contrast to these
expectations, we here find unpredictable, transiently chaotic dynamics induced
by SOT at an artificial anisotropy-engineered defect in a magnetic racetrack.
Based on these controlled conditions, we directly observe the nanoscale
dynamics with holography-based, time-resolved x-ray imaging. In concert with
micromagnetic simulations, we disclose a regime of violent picosecond
fluctuations, including topological instabilities that, remarkably, result in
deterministic final configurations. In addition, our images expose previously
unseen skyrmion shedding and highlight the potential of transiently chaotic
pathways for topological switching. Our approach offers new perspectives for
the investigation and application of highly non-linear SOT dynamics in
spintronics materials.
Only bosonic molecular species have been directly laser cooled to date,
primarily due to an abundance of bosonic isotopes in nature and to their
simpler hyperfine structure. Fermionic molecules provide new opportunities for
ultracold chemistry, quantum simulation, and precision measurements. Here we
report direct laser cooling of a fermionic molecular isotopologue, calcium
monodeuteride (CaD). With a nuclear spin I = 1, only 5 hyperfine states need to
be addressed for rotational closure in optical cycling. These hyperfine states
are unresolved for typical experimental linewidths. We present a method for
efficiently producing alkaline-earth metal hydrides and deuterides. We
demonstrate rotational closure and show magnetically assisted Sisyphus cooling
in one dimension for a beam of CaD molecules. Our results indicate that the
experimental complexity for laser cooling CaD is similar to that of calcium
monohydride (CaH). Laser cooling of CaD is a promising first step for
production of ultracold and trapped atomic deuterium.
We have theoretically investigated the spin- and valley-dependent
superfluidity properties of indirect momentum space dark dipolar excitons in
double layers with massive anisotropic tilted semi-Dirac bands in the presence
of circularly polarized irradiation. An external vertical electric field is
also applied to the structure and is responsible for tilting and gap opening
for the band structure. For our calculations we used the parameters of a double
layer of 1T$^\prime$-MoS$_2$. Closed form analytical expressions are presented
for the energy spectrum for excitons, their associated wave functions and
binding energies. Additionally, we examine the effects which the intensity and
frequency of circularly polarized irradiation has for 1T$^\prime$-MoS$_2$ on
the effective mass of the excitons since it has been demonstrated that the
application of an external high-frequency dressing field tailors the crucial
electronic including the exciton binding energy, as well as the critical
temperature for superfluidity. We also calculate the sound velocity in the
anisotropic weakly-interacting Bose gas of two-component indirect momentum
space dark excitons for a double layer of 1T$^\prime$-MoS$_2$. We show that the
critical velocity of superfluidity, the spectrum of collective excitations,
concentrations of the superfluid and normal component, and mean field critical
temperature for superfluidity are anisotropic and formed by a two-component
system. The critical temperature for superfluidity is increased when the
exciton concentration and interlayer separation are increased. We propose the
use of phonon-assisted photoluminescence to experimentally confirm directional
superfluidity of indirect momentum space dark excitons in a double layer with
massive anisotropic tilted semi-Dirac bands.
How electronic topology develops in strongly correlated systems represents a
fundamental challenge in the field of quantum materials. Recent studies have
advanced the characterization and diagnosis of topology in Mott insulators
whose underlying electronic structure is topologically nontrivial, through
``Green's function zeros". However, their counterparts in metallic systems have
yet to be explored. Here, we address this problem in an orbital-selective Mott
phase (OSMP), which is of extensive interest to a variety of strongly
correlated systems with a short-range Coulomb repulsion. We demonstrate
symmetry protected crossing of the zeros in an OSMP. Utilizing the concept of
Green's function Berry curvature, we show that the zero crossing has a
quantized Berry flux. The resulting notion of Dirac zeros provides a window
into the largely hidden landscape of topological zeros in strongly correlated
metallic systems and, moreover, opens up a means to diagnose strongly
correlated topology in new materials classes.
Wrinkling, creasing and folding are frequent phenomena encountered in
biological and man-made bilayers made by thin films bonded to thicker and
softer substrates often containing fibers. Paradigmatic examples of the latter
are the skin, the brain, and arterial walls, for which wiggly cross-sections
are detected. Although experimental investigations on corrugation of these and
analog bilayers would greatly benefit from scaling laws for prompt comparison
of the wrinkling features, neither are they available nor have systematic
approaches yielding to such laws ever been provided before. This gap is filled
in this paper, where a uniaxially compressed bilayer formed by a thin elastic
film bonded on a hyperelastic fiber-reinforced substrate is considered. The
force balance at the film-substrate interface is here analytically and
numerically investigated for highly mismatched film-substrates. The onset of
wrinkling is then characterized in terms of both the critical strain and its
corresponding wavenumber. Inspired by the asymptotic laws available for
neo-Hookean bilayers, the paper then provides a systematic way to achieve novel
scaling laws for the wrinkling features for fiber-reinforced highly mismatched
hyperelastic bilayers. Such novel scaling laws shed light on the key
contributions defining the response of the bilayer, as it is characterized by a
fiber-induced complex anisotropy. Results are compared with Finite Element
Analyses and also with outcomes of both existing linear models and available
adhoc scalings. Furthermore, the amplitude, the global maximum and minimum of
ruga occurring under increasing compression spanning the wrinkling, period
doubling and folding regimes are also obtained.
We investigate gap-closings in one- and two-dimensional tight-binding models
with two bands, containing non-Hermitian hopping terms, and open boundary
conditions (OBCs) imposed along one direction. We compare the bulk OBC spectra
with the periodic boundary condition (PBC) spectra, pointing out that they do
not coincide, which is an intrinsic characteristic of non-Hermitian systems.
The non-Hermiticity thus results in the failure of the familiar notions of
bulk-boundary correspondence found for Hermitian systems. This necessitates the
search for topological invariants which can characterize gap-closings in open
non-Hermitian systems correctly and unambiguously. We elucidate the behaviour
of two possible candidates applicable for one-dimensional slices -- (1) the sum
of winding numbers for the two bands defined on a generalized Brillouin zone
and (2) the biorthogonal polarization (BP). While the former shows
jumps/discontinuities for some of the non-Hermitian systems studied here, at
points when an edge mode enters the bulk states and becomes delocalized, it
does not maintain quantized values in a given topological phase. On the
contrary, BP shows jumps and at phase transitions takes the quantized value of
one or zero, which corresponds to whether an actual edge mode exists or whether
that mode is delocalized and absorbed within the bulk (not being an edge mode
anymore).
We analytically solve the Landau-Lifshitz equations for the collective
magnetization dynamics in a synthetic antiferromagnet (SAF) nanoparticle and
uncover a regime of barrier-free switching under a short small-amplitude
magnetic field pulse applied perpendicular to the SAF plane. We give examples
of specific implementations for forming such low-power and ultra-fast switching
pulses. For fully optical, resonant, barrier-free SAF switching we estimate the
power per write operation to be $ \sim 100 $ pJ, 10-100 times smaller than for
conventional quasi-static rotation, which should be attractive for memory
applications.
The organization of interphase chromosomes in a number of species is starting
to emerge thanks to advances in a variety of experimental techniques. However,
much less is known about the dynamics, especially in the functional states of
chromatin. Some experiments have shown that the motility of individual loci in
human interphase chromosome decreases during transcription, and increases upon
inhibiting transcription. This is a counter-intuitive finding because it is
thought that the active mechanical force ($F$) on the order of ten
pico-newtons, generated by RNA polymerase II (RNAPII) that is presumably
transmitted to the gene-rich region of the chromatin, would render it more
open, thus enhancing the mobility. We developed a minimal active copolymer
model for interphase chromosomes to investigate how $F$ affects the dynamical
properties of chromatin. The movements of the loci in the gene-rich region are
suppressed in an intermediate range of $F$, and are enhanced at small $F$
values, which has also been observed in experiments. In the intermediate $F$,
the bond length between consecutive loci increases, becoming commensurate with
the distance at the minimum of the attractive interaction between non-bonded
loci. This results in a transient disorder-to-order transition, leading to a
decreased mobility during transcription. Strikingly, the $F$-dependent change
in the locus dynamics preserves the organization of the chromosome at $F=0$.
Transient ordering of the loci, which is not found in the polymers with random
epigenetic profiles, in the gene-rich region might be a plausible mechanism for
nucleating a dynamic network involving transcription factors, RNAPII, and
chromatin.
In this work we derive braid group representations and Stokes matrices for
Liouville conformal blocks with one irregular operator. By employing the
Coulomb gas formalism, the corresponding conformal blocks can be interpreted as
wavefunctions of a Landau-Ginzburg model specified by a superpotential
$\mathcal{W}$. Alternatively, these can also be viewed as wavefunctions of a 3d
TQFT on a 3-ball with boundary a 2-sphere on which the operator insertions
represent Anyons whose fusion rules describe novel topological phases of
matter.
Topological invariants such as winding numbers and linking numbers appear as
charges of topological solitons in diverse nonlinear physical systems described
by a unit vector field defined on two and three dimensional manifolds. While
the Gauss-Bonnet theorem shows that the Euler characteristic (a topological
invariant) can be written as the integral of the Gaussian curvature (an
intrinsic geometric quantity), the intriguing question of whether winding and
linking numbers can also be expressed similarly as integrals of some intrinsic
geometric quantities has not been addressed in the literature. In this paper we
provide the answer by showing that for the winding number in two dimensions,
these quantities are torsions of the two evolving space curves describing the
manifold. On the other hand, in three dimensions we find that in addition to
torsions, intrinsic twists of the space curves are necessary to obtain a
nontrivial winding number and linking number. These new results arise from the
hitherto unknown connections that we establish between these topological
invariants and the corresponding appropriately normalized global anholonomies
(i.e., geometric phases) associated with the unit vector fields on the
respective manifolds. An application of our results to a 3D Heisenberg
ferromagnetic model supporting a topological soliton is also presented.
Compounds with kagome lattice structure are known to exhibit Dirac cones,
flat bands, and van Hove singularities, which host numerous versatile quantum
phenomena. Inspired by these intriguing properties, we investigate the
temperature and magnetic field dependent electrical transports along with the
theoretical calculations of ScV6Sn6, a nonmagnetic charge density wave (CDW)
compound. At low temperatures, the compound exhibits Shubnikov-de Haas quantum
oscillations, which help to design the Fermi surface (FS) topology. This
analysis reveals the existence of several small FSs in the Brillouin zone,
combined with a large FS. Among them, the FS possessing Dirac band is a
non-trivial and generates a non-zero Berry phase. In addition, the compound
also shows the anomalous Hall-like behaviour up to the CDW with the CDW phase,
ScV6Sn6 presents a unique material example of the versatile HfFe6Ge6 family and
provides various promising opportunities to explore the series further.
We study the quantum Hall effect in a two-dimensional homogeneous electron
gas coupled to a quantum cavity field. As initially pointed out by Kohn,
Galilean invariance for a homogeneous quantum Hall system implies that the
electronic center of mass (CM) decouples from the electron-electron
interaction, and the energy of the CM mode, also known as Kohn mode, is equal
to the single particle cyclotron transition. In this work, we point out that
strong light-matter hybridization between the Kohn mode and the cavity photons
gives rise to collective hybrid modes between the Landau levels and the
photons. We provide the exact solution for the collective Landau polaritons and
we demonstrate the weakening of topological protection at zero temperature due
to the existence of the lower polariton mode which is softer than the Kohn
mode. This provides an intrinsic mechanism for the recently observed
topological breakdown of the quantum Hall effect in a cavity [Appugliese et
al., Science 375, 1030-1034 (2022)]. Importantly, our theory predicts the
cavity suppression of the thermal activation gap in the quantum Hall transport.
Our work paves the way for future developments in the cavity control of quantum
materials.
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
two-body loss. We show that, in the presence of complex-valued interactions,
eigenmodes and eigenvalues of the Liouvillian strongly depend on boundary
conditions. Specifically, we find that complex-valued interactions induce
localization of eigenmodes of the Liouvillian around the right edge under open
boundary conditions. To characterize the Liouvllian skin effect, we define the
topological invariant by using the Liouvillian superoperator. Then, we
numerically confirm that the topological invariant captures the Liouvillian
skin effect. Furthermore, the presence of the localization of eigenmodes
results in the unique dynamics observed only under open boundary conditions:
particle accumulation at the right edge in transient dynamics. Our result paves
the way to realize topological phenomena in open quantum systems induced by
strong interactions.
In this study, we systematically investigated the mechanical responses of
monolayer molybdenum ditelluride (MoTe2) using molecular dynamics (MD)
simulations. The tensile behavior of trigonal prismatic phase (2H phase) MoTe2
under uniaxial strain was simulated in the armchair and zigzag directions. We
also investigated the crack formation and propagation in both armchair and
zigzag directions at 10K and 300K to understand the fracture behavior of
monolayer MoTe2 at different temperatures. The MD simulations show clean
cleavage for the armchair direction, and the cracks were numerous and scattered
in the case of the zigzag direction. Finally, we investigated the effect of
temperature on Young's modulus and fracture stress of monolayer MoTe2. The
results show that at a strain rate of 10^-4 ps^-1, the fracture strength of
monolayer MoTe2 in the armchair and zigzag directions at 10K is 16.33 GPa
(11.43 N/m) and 13.71 GPa (9.46 N/m) under a 24% and 18% fracture strain,
respectively. The fracture strength of monolayer MoTe2 in the armchair and
zigzag direction at 600K is 10.81 GPa (7.56 N/m) and 10.13 GPa (7.09 N/m) under
a 12.5% and 12.47% fracture strain, respectively.
The valley Hall effect arises from valley contrasting Berry curvature and
requires inversion symmetry breaking. Here, we propose a nonlinear mechanism to
generate a valley Hall current in systems with both inversion and time-reversal
symmetry, where the linear and second-order charge Hall currents vanish along
with the linear valley Hall current. We show that a second-order valley Hall
signal emerges from the electric field correction to the Berry curvature,
provided a valley-contrasting anisotropic dispersion is engineered. We
demonstrate the nonlinear valley Hall effect in tilted massless Dirac fermions
in strained graphene and organic semiconductors. Our work opens up the
possibility of controlling the valley degree of freedom in inversion symmetric
systems via nonlinear valleytronics.
Higher-order topological properties of two-dimensional(2D) magnetic materials
have recently been proposed. In 2D ferromagnetic Janus materials, we find that
ScClI is a second-order topological insulator (SOTI). By means of a
multi-orbital tight-binding model, we analyze the orbital contributions of
higher-order topologies. Further, we give the complete high-order topological
phase diagram of ScClI, based on the external field modulation of the
magneto-valley coupling and energy levels. 2D ScClI has a pronounced valley
polarization, which causes different insulating phases to exhibit completely
different anomalous Nernst conductance. As a result, we use the matched
anomalous Nernst effect to reveal the topological phase transition process of
ScClI. We utilize the characteristics of valley electronics to link
higher-order topological materials with the anomalous Nernst effect, which has
potential implications for high-order topological insulators and valley
electronics.
We induce and study a topological dynamical phase transition between two
planar superconducting phases. Using the
Lindblad equation to account for the interactions of Bogoliubov
quasiparticles among themselves
and with the fluctuations of the superconducting order parameter, we derive
the relaxation dynamics
of the order parameter. To characterize the phase transition, we compute the
fidelity and the
spin-Hall conductance of the open system.
Our approach provides crucial informations for experimental implementations,
such as
the dependence of the critical time on the system-bath coupling.
Extracting Hamiltonian parameters from available experimental data is a
challenge in quantum materials. In particular, real-space spectroscopy methods
such as scanning tunneling spectroscopy allow probing electronic states with
atomic resolution, yet even in those instances extracting effective Hamiltonian
is an open challenge. Here we show that impurity states in modulated systems
provide a promising approach to extracting non-trivial Hamiltonian parameters
of a quantum material. We show that by combining the real-space spectroscopy of
different impurity locations in a moire topological superconductor, modulations
of exchange and superconducting parameters can be inferred via machine
learning. We demonstrate our strategy with a physically-inspired harmonic
expansion combined with a fully-connected neural network that we benchmark
against a conventional convolutional architecture. We show that while both
approaches allow extracting exchange modulations, only the former approach
allows inferring the features of the superconducting order. Our results
demonstrate the potential of machine learning methods to extract Hamiltonian
parameters by real-space impurity spectroscopy as local probes of a topological
state.
The experimental characterization of quantum spin liquids poses significant
challenges due to the absence of long-range magnetic order, even at absolute
zero temperature. The identification of these states of matter often relies on
the analysis of their excitations. In this paper, we propose a method for
detecting the signatures of the fractionalized excitations in quantum spin
liquids using a tunneling spectroscopy setup. Inspired by the recent
development of the quantum twisting microscope, we consider a planar tunneling
junction, in which a candidate quantum spin liquid material is placed between
two graphene layers. By tuning the relative twist angle and voltage bias
between the leads, we can extract the dynamical spin structure factor of the
tunneling barrier with momentum and energy resolution. Our proposal presents a
promising tool for experimentally characterizing quantum spin liquids in
two-dimensional materials.
The recent claim of room temperature superconductivity in a copper-doped lead
apatite compound, called LK-99, has sparked remarkable interest and
controversy. Subsequent experiments have largely failed to reproduce the
claimed superconductivity, while theoretical works have identified multiple key
features including strong electronic correlation, structural instabilities, and
dopability constraints. A puzzling claim of several recent theoretical studies
is that both parent and copper-doped lead apatite structures are dynamically
unstable at the harmonic level, questioning decades of experimental reports of
the parent compound structures and the recently proposed copper-doped
structures. In this work, we demonstrate that both parent and copper-doped lead
apatite structures are dynamically stable at room temperature. Anharmonic
phonon-phonon interactions play a key role in stabilizing some copper-doped
phases, while most phases are largely stable even at the harmonic level. We
also show that dynamical stability depends on both volume and correlation
strength, suggesting controllable ways of exploring the copper-doped lead
apatite structural phase diagram. Our results fully reconcile the theoretical
description of the structures of both parent and copper-doped lead apatite with
experiment.
We studied the single-particle Anderson localization problem for
non-Hermitian systems on directed graphs. Random regular graph and various
undirected standard random graph models were modified by controlling
reciprocity and hopping asymmetry parameters. We found the emergence of left,
biorthogonal and right localized states depending on both parameters and graph
structure properties such as node degree $d$. For directed random graphs, the
occurrence of biorthogonal localization near exceptional points is described
analytically and numerically. The clustering of localized states near the
center of the spectrum and the corresponding mobility edge for left and right
states are shown numerically. Structural features responsible for localization,
such as topologically invariant nodes or drains and sources, were also
described. Considering the diagonal disorder, we observed the disappearance of
localization dependence on reciprocity around $W \sim 20$ for a random regular
graph $d=4$. With a small diagonal disorder, the average biorthogonal fractal
dimension drastically reduces. Around $W \sim 5$ localization scars occur
within the spectrum, alternating as vertical bands of clustering of left and
right localized states.
The Einstein-de Haas (EdH) effect is a fundamental, mechanical consequence of
any temporal change of magnetism in an object. EdH torque results from
conserving the object's total angular momentum: the angular momenta of all the
specimen's magnetic moments, together with its mechanical angular momentum.
Although the EdH effect is usually small and difficult to observe, it increases
in magnitude with detection frequency. We explore the frequency-dependence of
EdH torque for a thin film permalloy microstructure by employing a ladder of
flexural beam modes (with five distinct resonance frequencies spanning from 3
to 208 MHz) within a nanocavity optomechanical torque sensor via magnetic
hysteresis curves measured at mechanical resonances. At low DC fields the
gyrotropic resonance of a magnetic vortex spin texture overlaps the 208 MHz
mechanical mode. The massive EdH mechanical torques arising from this
co-resonance yield a fingerprint of vortex core pinning and depinning in the
sample. The experimental results are discussed in relation to mechanical
torques predicted from both macrospin (at high DC magnetic field) and
finite-difference solutions to the Landau-Lifshitz-Gilbert (LLG) equation. A
global fit of the LLG solutions to the frequency-dependent data reveals a
statistically significant discrepancy between the experimentally observed and
simulated torque phase behaviours at spin texture transitions that can be
reduced through the addition of a time constant to the conversion between
magnetic cross-product torque and mechanical torque, constrained by experiment
to be in the range of 0.5 - 4 ns.
This perspective article reviews arguments that glass-forming liquids are
different from those of standard liquid-state theory, which typically have a
viscosity in the mPa$\cdot$s range and relaxation times of order picoseconds.
These numbers grow dramatically and become $10^{12}-10^{15}$ times larger for
liquids cooled toward the glass transition. This translates into a qualitative
difference, and below the ``solidity length'' which is of order one micron at
the glass transition, a glass-forming liquid behaves much like a solid. Recent
numerical evidence for the solidity of ultraviscous liquids is reviewed, and
experimental consequences are discussed in relation to dynamic heterogeneity,
frequency-dependent linear-response functions, and the temperature dependence
of the average relaxation time.
Characteristic properties of secondary electrons emitted from irradiated
two-dimensional materials arise from multi-length and time-scale relaxation
processes that connect the initial non-equilibrium excited electron
distribution with their eventual emission. To understand these processes, which
are critical for using secondary electrons as high-resolution thermalization
probes, we combine first-principles real-time electron dynamics with modern
experiments. Our data for cold and hot proton-irradiated graphene shows
signatures of kinetic and potential emission and generally good agreement for
electron yields between experiment and theory. The duration of the emission
pulse is about 1.5 femtoseconds, indicating high time resolution when used as a
probe. Our newly developed method to predict kinetic energy spectra shows good
agreement with electron and ion irradiation experiments and prior models. We
find that lattice temperature significantly increases secondary electron
emission, whereas electron temperature has a negligible effect.
In this work, we study the near-field radiative energy, linear-momentum, and
angular-momentum transfer from a current-biased graphene to nanoparticles. The
electric current through the graphene sheet induces nonequilibrium
fluctuations, causing energy and momentum transfer even in the absence of a
temperature difference. The inherent spin-momentum locking of graphene surface
plasmons leads to an in-plane torque perpendicular to the direction of the
electric current. In the presence of a temperature difference, the energy
transfer is greatly enhanced while the lateral force and torque remains within
the same order. Our work explores the potential of utilizing current-biased
graphene to manipulate nanoparticles.
The complex correlated charge density wave (CDW) phases of 1T-TaS2 have
attracted great attention due to their emergent quantum states, such as
intricate CDW phase, Mott-Hubbard state, superconductivity and quantum spin
liquid. The delicate interplay among the complex intra-/inter-layer
electron-electron and electron-lattice interactions is the fundamental
prerequisite of these exotic quantum states. Here, we report a real-space
titration-like investigation of correlated CDW state in 1T-TaS2 upon
hole-doping via low-temperature scanning tunneling microscopy (LT-STM). The
gradual increased hole-doping results in the sequential emergence of electron
voids, phase domains, stacking disordering and mixed phase/chiral domains
attributed to the reduced electron correlations. The achiral intermediate
ring-like clusters and nematic CDW states emerge at the intralayer chiral
domain wall and interlayer heterochiral stacking regions via the
chiral-overlapping configurations. The local reversible CDW manipulation is
further realized by the non-equilibrium transient charge-injections of STM
field-emission spectra. Our results provide an in-depth insight of this
intricate correlated CDW state, and pave a way to realize exotic quantum states
via the accurate tuning of interior interactions in correlated materials.
With the rapidly expanded field of two-dimensional(2D) magnetic materials,
the frustrated magnetic skyrmions are attracting growing interest recently.
Here, based on hexagonal close-packed (HCP) lattice of $J_1$-$J_2$ Heisenberg
spins model, we systematically investigate the frustrated skyrmions and phase
transition by micromagnetic simulations and first-principles calculations. The
results show that four spin phases of antiferromagnetic, labyrinth domain,
skyrmion and ferromagnetic textures are determined by the identified ranges of
$J_1$-$J_2$. Importantly, skyrmion phase with an increasing topological number
($Q$) covers a wider $J_1$-$J_2$ area. Then, the diameter of skyrmions can be
tuned by the frustration strength ($|J_2/J_1|$) or external magnetic field.
Besides, a phase transition from N$\acute{e}$el to Bloch type skyrmion is
observed due to the change of the helicity with the variation of $|J_2/J_1|$.
Furthermore, as increasing magnetic field, the skyrmions with high $Q$ ($\ge
3$) tend to split into the ones with $Q=1$, thereby achieving a lower
systematic energy. Additionally, we find that the CoCl$_2$ monolayer satisfies
the requirement of the frustrated $J_1$-$J_2$ magnet, and the related magnetic
behaviors agree with the above conclusions. The frustration-induced skyrmions
are stable without the manipulation of temperature and magnetic field. Our
results may open a possible way toward spintronic applications based on
High-topological-number and nanoscale topological spin textures of skyrmions.

Date of feed: Tue, 23 Jan 2024 01:30:00 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) **Topological pumping induced by spatiotemporal modulation of interaction. (arXiv:2401.10906v1 [cond-mat.mes-hall])**

Boning Huang, Yongguan Ke, Wenjie Liu, Chaohong Lee

**Machine Learning of Knot Topology in Non-Hermitian Band Braids. (arXiv:2401.10908v1 [cond-mat.mes-hall])**

Jiangzhi Chen, Zi Wang, Yu-Tao Tan, Ce Wang, Jie Ren

**Reply to "Comment on `Anomalous Reentrant 5/2 Quantum Hall Phase at Moderate Landau-Level-Mixing Strength' ". (arXiv:2401.10912v1 [cond-mat.mes-hall])**

Sudipto Das, Sahana Das, Sudhansu S. Mandal

**Symmetry-induced higher-order exceptional points in two dimensions. (arXiv:2401.10913v1 [cond-mat.mes-hall])**

Anton Montag, Flore K. Kunst

**Comment on "Deformations of the spin currents by topological screw dislocation and cosmic dispiration''. (arXiv:2401.10919v1 [cond-mat.mes-hall])**

R. R. S. Oliveira

**A scale-invariant large-area single-mode topological photonic cavity. (arXiv:2401.10928v1 [cond-mat.mes-hall])**

Zhongfu Li, Shiqi Li, Bei Yan, Hsun-Chi Chan, Jing Li, Jun Guan, Wengang Bi, Yuanjiang Xiang, Zhen Gao, Shuang Zhang, Peng Zhan, Zhenlin Wang, Biye Xie

**Mixed state topological order parameters for symmetry protected fermion matter. (arXiv:2401.10993v1 [cond-mat.quant-gas])**

Ze-Min Huang, Sebastian Diehl

**Hybridized magnonic materials for THz frequency applications. (arXiv:2401.11010v1 [cond-mat.mtrl-sci])**

D.-Q. To, A. Rai, J. M. O. Zide, S. Law, J. Q. Xiao, M. B. Jungfleisch, M. F. Doty

**Anti-Jahn-Teller disproportionation and prospects for spin-triplet superconductivity in d-element compounds. (arXiv:2401.11028v1 [cond-mat.supr-con])**

A. S. Moskvin, Yu. D. Panov

**Emergent bright excitons with Rashba spin-orbit coupling in atomic monolayers. (arXiv:2401.11079v1 [cond-mat.mes-hall])**

Jiayu David Cao, Gaofeng Xu, Benedikt Scharf, Konstantin Denisov, Igor Zutic

**Pressure dependent physical properties of a potential high-TC superconductor ScYH6: insights from first-principles study. (arXiv:2401.11121v1 [cond-mat.mtrl-sci])**

Md. Ashraful Alam, F. Parvin, S. H. Naqib

**Valley filtering and valley valves in irradiated pristine graphene. (arXiv:2401.11136v1 [cond-mat.mes-hall])**

Rekha Kumari, Gopal Dixit, Arijit Kundu

**Quasiparticle scattering in three-dimensional topological insulators near the thickness limit. (arXiv:2401.11157v1 [cond-mat.mes-hall])**

Haiming Huang, Mu Chen, Dezhi Song, Jun Zhang, Ye-ping Jiang

**Radiation of a short linear antenna above a topologically insulating half-space. (arXiv:2401.11285v1 [cond-mat.mes-hall])**

M. Ibarra-Meneses, A. Martín-Ruiz

**Optimization of random cost functions and statistical physics. (arXiv:2401.11348v1 [cond-mat.dis-nn])**

Andrea Montanari

**Exploring Intrinsic Magnetic Topological Insulators: The Case of EuIn$_2$As$_2$. (arXiv:2401.11386v1 [cond-mat.str-el])**

Hao Liu, Qi-Yi Wu, Chen Zhang, Jie Pang, Bo Chen, Jiao-Jiao Song, Yu-Xia Duan, Ya-Hua Yuan, Hai-Yun Liu, Chuan-Cun Shu, Yuan-Feng Xu, You-Guo Shi, Jian-Qiao Meng

**Correcting force error-induced underestimation of lattice thermal conductivity in machine learning molecular dynamics. (arXiv:2401.11427v1 [cond-mat.mtrl-sci])**

Xiguang Wu, Wenjiang Zhou, Haikuang Dong, Penghua Ying, Yanzhou Wang, Bai Song, Zheyong Fan, Shiyun Xiong

**Hydrostatic pressure effect on structural and transport properties of co-existing layered and disordered rock-salt phase of LixCoO2. (arXiv:2401.11446v1 [cond-mat.mtrl-sci])**

Thiagarajan Maran (1), A. Jain (2 and 3), Muthukumaran Sundaramoorthy (1 and 5), A. P. Roy (4), Boby Joseph (5), Govindaraj Lingannan (1), Ashwin Mohan (6), D. Bansal (4), S. M. Yusuf (2 and 3), Arumugam Sonachalam (1 and 7). ( (1) Center for High Pressure Research, Bharathidasan University, Tiruchirappalli, India, (2) Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, India, (3) Homi Bhabha National Institute, Mumbai, India, (4) Department of Mechanical Engineering, Indian Institute of Technology Bombay, Mumbai, India, (5) Elettra - Sincrotrone Trieste, Bosavizza, Italy, (6) Department of Physics, Institute of Chemical Technology, Mumbai, India, (7) Tamil Nadu Open University, Chennai, India. )

**Reentrant quantum anomalous Hall effect in molecular beam epitaxy-grown MnBi2Te4 thin films. (arXiv:2401.11450v1 [cond-mat.mes-hall])**

Yuanzhao Li, Yunhe Bai, Yang Feng, Jianli Luan, Zongwei Gao, Yang Chen, Yitian Tong, Ruixuan Liu, Su Kong Chong, Kang L. Wang, Xiaodong Zhou, Jian Shen, Jinsong Zhang, Yayu Wang, Chui-Zhen Chen, XinCheng Xie, Xiao Feng, Ke He, Qi-Kun Xue

**Fractal Surface States in Three-Dimensional Topological Quasicrystals. (arXiv:2401.11497v1 [cond-mat.mes-hall])**

Zhu-Guang Chen, Cunzhong Lou, Kaige Hu, Lih-King Lim

**Topological superconductors in trapped-ion system and their Floquet engineering. (arXiv:2401.11510v1 [quant-ph])**

Ming-Jian Gao, Yu-Peng Ma, Jun-Hong An

**Solvable Two-dimensional Dirac Equation with Matrix Potential: Graphene in External Electromagnetic Field. (arXiv:2401.11526v1 [cond-mat.mes-hall])**

Mikhail V. Ioffe, David N. Nishnianidze

**One-dimensional non-Hermitian band structures as Riemann surfaces. (arXiv:2401.11661v1 [math-ph])**

Heming Wang, Lingling Fan, Shanhui Fan

**Epitaxial growth and magnetic properties of kagome metal FeSn/elemental ferromagnet heterostructures. (arXiv:2401.11662v1 [cond-mat.mtrl-sci])**

Prajwal M. Laxmeesha, Tessa D. Tucker, Rajeev Kumar Rai, Shuchen Li, Myoung-Woo Yoo, Eric A. Stach, Axel Hoffmann, Steven J. May

**Emergent SU(3) topological system in a trimer SSH model. (arXiv:2401.11695v1 [cond-mat.mes-hall])**

Sonu Verma, Tarun Kanti Ghosh

**Gapless symmetry protected topological phases and generalized deconfined critical points from gauging a finite subgroup. (arXiv:2401.11702v1 [cond-mat.str-el])**

Lei Su, Meng Zeng

**Two New Members of the Covalent Organic Frameworks Family: Crystalline 2D-Oxocarbon and 3D-Borocarbon Structures. (arXiv:2401.11843v1 [cond-mat.mtrl-sci])**

N. Hassani, A. Movafegh-Ghadirli, Z. Mahdavifar, F. M. Peeters, M. Neek-Amal

**Quantum Hall criticality in an amorphous Chern insulator. (arXiv:2401.11855v1 [cond-mat.mes-hall])**

Soumya Bera, Johannes Dieplinger, Naba P Nayak

**Coexistence of Topological and Normal Insulating Phases in Electro-Optically Tuned InAs/GaSb Bilayer Quantum Wells. (arXiv:2401.11965v1 [cond-mat.mes-hall])**

Manuel Meyer, Tobias Fähndrich, Sebastian Schmid, Adriana Wolf, Sergey Krishtopenko, Benoit Jouault, Gerald Bastard, Frederic Teppe, Fabian Hartmann, Sven Höfling

**Nano-optical investigation of grain boundaries, strain and edges in CVD grown MoS$_{2}$ monolayers. (arXiv:2401.11984v1 [cond-mat.mtrl-sci])**

Frederico B. Sousa, Rafael Battistella Nadas, Rafael Martins, Ana P. M. Barboza, Jaqueline S. Soares, Bernardo R. A. Neves, Ive Silvestre, Ado Jorio, Leandro M. Malard

**Interplay of Landau quantization and interminivalley scatterings in a weakly coupled moir\'e superlattice. (arXiv:2401.12003v1 [cond-mat.mes-hall])**

Yalong Yuan, Le Liu, Jundong Zhu, Jingwei Dong, Yanbang Chu, Fanfan Wu, Luojun Du, Kenji Watanabe, Takashi Taniguchi, Dongxia Shi, Guangyu Zhang, Wei Yang

**Machine Learning Based Prediction of Polaron-Vacancy Patterns on the TiO$_2$(110) Surface. (arXiv:2401.12042v1 [cond-mat.mtrl-sci])**

Viktor C. Birschitzky, Igor Sokolovic, Michael Prezzi, Krisztian Palotas, Martin Setvin, Ulrike Diebold, Michele Reticcioli, Cesare Franchini

**Temperature as Joules per Bit. (arXiv:2401.12119v1 [quant-ph])**

Charles Alexandre Bédard, Sophie Berthelette, Xavier Coiteux-Roy, Stefan Wolf

**Machine-learning structural reconstructions for accelerated point defect calculations. (arXiv:2401.12127v1 [cond-mat.mtrl-sci])**

Irea Mosquera-Lois, Seán R. Kavanagh, Alex M. Ganose, Aron Walsh

**Time-Resolved Imaging Reveals Transiently Chaotic Spin-Orbit-Torque-Driven Dynamics Under Controlled Conditions. (arXiv:2401.12130v1 [cond-mat.mes-hall])**

Lisa-Marie Kern, Kai Litzius, Victor Deinhart, Michael Schneider, Christopher Klose, Kathinka Gerlinger, Riccardo Battistelli, Dieter Engel, Christian M. Günther, Meng-Jie Huang, Katja Höflich, Felix Büttner, Stefan Eisebitt, Bastian Pfau

**Laser cooling of a fermionic molecule. (arXiv:2401.12145v1 [physics.atom-ph])**

Jinyu Dai, Qi Sun, Benjamin C. Riley, Debayan Mitra, Tanya Zelevinsky

**Superfluidity of indirect momentum space dark dipolar excitons in a double layer with massive anisotropic tilted semi-Dirac bands. (arXiv:2401.12154v1 [cond-mat.mes-hall])**

A. Nafis Arafat, Oleg L. Berman, Godfrey Gumbs

**Dirac zeros in an orbital selective Mott phase: Green's function Berry curvature and flux quantization. (arXiv:2401.12156v1 [cond-mat.str-el])**

Lei Chen, Haoyu Hu, Maia G. Vergniory, Jennifer Cano, Qimiao Si

**Toward new scaling laws for wrinkling in biologically relevant fiber-reinforced bilayers. (arXiv:2401.12157v1 [cond-mat.soft])**

A. Mirandola, A. Cutolo, A. R. Carotenuto, N. Nguyen, L. Pocivavsek, M. Fraldi, L. Deseri

**Identifying gap-closings in open non-Hermitian systems by Biorthogonal Polarization. (arXiv:2401.12213v1 [quant-ph])**

Ipsita Mandal

**Fast barrier-free switching in synthetic antiferromagnets. (arXiv:2110.02138v3 [cond-mat.mes-hall] UPDATED)**

Yu. Dzhezherya, V. Kalita, P. Polynchuk, A. Kravets, V. Korenivski, S. Kruchinin, S. Bellucci

**Transcription-induced active forces suppress chromatin motion. (arXiv:2205.00353v4 [physics.bio-ph] UPDATED)**

Sucheol Shin, Guang Shi, Hyun Woo Cho, D. Thirumalai

**Liouville conformal blocks and Stokes phenomena. (arXiv:2301.07957v2 [hep-th] UPDATED)**

Xia Gu, Babak Haghighat

**Twisted curve geometry underlying topological invariants. (arXiv:2304.06240v3 [nlin.PS] UPDATED)**

Radha Balakrishnan, Rossen Dandoloff, Avadh Saxena

**Quantum oscillations revealing topological band in kagome metal ScV6Sn6. (arXiv:2305.04683v2 [cond-mat.mtrl-sci] UPDATED)**

Changjiang Yi, Xiaolong Feng, Ning Mao, Premakumar Yanda, Subhajit Roychowdhury, Yang Zhang, Claudia Felser, Chandra Shekhar

**Weakened Topological Protection of the Quantum Hall Effect in a Cavity. (arXiv:2305.10558v3 [cond-mat.mes-hall] UPDATED)**

Vasil Rokaj, Jie Wang, John Sous, Markus Penz, Michael Ruggenthaler, Angel Rubio

**Interaction-induced Liouvillian skin effect in a fermionic chain with a two-body loss. (arXiv:2305.19697v2 [cond-mat.str-el] UPDATED)**

Shu Hamanaka, Kazuki Yamamoto, Tsuneya Yoshida

**Temperature Dependent Failure of Atomically Thin MoTe2. (arXiv:2306.14733v3 [cond-mat.mtrl-sci] UPDATED)**

A S M Redwan Haider, Ahmad Fatehi Ali Mohammed Hezam, Md Akibul Islam, Yeasir Arafat, Mohammad Tanvirul Ferdaous, Sayedus Salehin, Md.Rezwanul Karim

**Nonlinear Valley Hall Effect. (arXiv:2307.12088v2 [cond-mat.mes-hall] UPDATED)**

Kamal Das, Koushik Ghorai, Dimitrie Culcer, Amit Agarwal

**High-Order Topological Phase Diagram Revealed by Anomalous Nernst Effect in Janus ScClI Monolayer. (arXiv:2308.07550v2 [cond-mat.mes-hall] UPDATED)**

Ning-Jing Yang, Jian-Min Zhang

**Dissipation driven dynamical topological phase transitions in two-dimensional superconductors. (arXiv:2308.08265v2 [cond-mat.str-el] UPDATED)**

Andrea Nava, Carmine Antonio Perroni, Reinhold Egger, Luca Lepori, Domenico Giuliano

**Hamiltonian learning with real-space impurity tomography in topological moire superconductors. (arXiv:2308.11400v2 [cond-mat.mes-hall] UPDATED)**

Maryam Khosravian, Rouven Koch, Jose L. Lado

**Probing quantum spin liquids with a quantum twisting microscope. (arXiv:2308.15533v2 [cond-mat.str-el] UPDATED)**

Valerio Peri, Shahal Ilani, Patrick A. Lee, Gil Refael

**On the dynamical stability of copper-doped lead apatite. (arXiv:2309.11541v3 [cond-mat.supr-con] UPDATED)**

Sun-Woo Kim, Kang Wang, Siyu Chen, Lewis J. Conway, G. Lucian Pascut, Ion Errea, Chris J. Pickard, Bartomeu Monserrat

**Localization transition in non-Hermitian systems depending on reciprocity and hopping asymmetry. (arXiv:2310.03412v2 [cond-mat.dis-nn] UPDATED)**

Daniil Kochergin, Vasilii Tiselko, Arsenii Onuchin

**Einstein-de Haas torque as a discrete spectroscopic probe allows nanomechanical measurement of a magnetic resonance. (arXiv:2310.18546v2 [cond-mat.mes-hall] UPDATED)**

K.R. Fast, J.E. Losby, G. Hajisalem, P.E. Barclay, M.R. Freeman

**Solid-that-flows picture of glass-forming liquids. (arXiv:2311.14460v3 [cond-mat.soft] UPDATED)**

Jeppe C. Dyre

**Non-equilibrium dynamics of electron emission from cold and hot graphene under proton irradiation. (arXiv:2311.18784v2 [cond-mat.mtrl-sci] UPDATED)**

Yifan Yao, Alina Kononov, Arne Metzlaff, Andreas Wucher, Lukas Kalkhoff, Lars Breuer, Marika Schleberger, André Schleife

**Current-induced near-field radiative energy, linear-momentum, and angular-momentum transfer. (arXiv:2312.07954v2 [physics.optics] UPDATED)**

Huimin Zhu, Gaomin Tang, Lei Zhang, Jun Chen

**Real-space hole-doping titration and manipulation of correlated charge density wave state in 1T-TaS2. (arXiv:2401.01507v3 [cond-mat.str-el] UPDATED)**

Haoyu Dong, Yanyan Geng, Jianfeng Guo, Le Lei, Yan Li, Li Huang, Fei Pang, Rui Xu, Weiqiang Yu, Wei Ji, Hong-Jun Gao, Weichang Zhou, Zhihai Cheng

**High-topological-number skyrmions and phase transition in two-dimensional frustrated $J_1$-$J_2$ magnets. (arXiv:2401.05719v3 [physics.comp-ph] UPDATED)**

Hongliang Hu, Zhong Shen, Zheng Chen, Xiaoping Wu, Tingting Zhong, Changsheng Song

Found 8 papers in prb Exhaustive study of topological semimetal (TSM) phases of matter in equilibriated electonic systems and myriad extensions has built upon the foundations laid by earlier introduction and study of Weyl semimetals, with broad applications in topologically protected quantum computing, spintronics, and o… Higher-order Weyl semimetal (HOWSM) is a fascinating topological phase that connects the nontrivial higher-order topology and Weyl semimetal. In this paper, we introduce a novel phase termed higher-order double-Weyl semimetals (HODWSMs) through the application of symmetry analysis and a minimal tigh… We analyze the two-body spectrum within the Hofstadter-Hubbard model on a square lattice through an exact variational ansatz and study the topological properties of its low-lying two-body bound-state branches. In particular, we discuss how the Hofstadter-Hubbard butterfly of the two-body branches ev… In this constantly expanding and evolving era of advanced technology, there is great demand for a compound that boasts a plethora of exotic properties. To procure such a compound, we conducted a thorough analysis of the lattice and electronic properties of several Th-based compounds using first-prin… The physical origin of the fractional quantum Hall effect at the half-filled lowest Landau level in wide quantum wells has remained a puzzle since its discovery three decades ago. This work presents quantitative calculations supporting the formation of a $p$-wave topological “superconductor” of composite fermions (CFs) here. CFs are predicted to form $f$-wave pairs at the quarter-filled Landau level in wide quantum wells. CF pairing is thus seen as the principal mechanism underlying the even-denominator fractional quantum Hall effect. Magnetic topological insulators in the quantum anomalous Hall regime host ballistic chiral edge channels. When proximitized by an $s$-wave superconductor, these edge states offer the potential for realizing topological superconductivity and Majorana bound states without the detrimental effect of lar… Using scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), and density functional theory (DFT), we demonstrate the formation of quasicrystalline gallium adlayer on icosahedral ($i$)-Al-Pd-Mn. Quasiperiodic motifs are evident in the STM topography images, including the Ga whit… The thermal properties of bilayer graphene (BLG) play a crucial role in the advancement of its promising electronic devices. However, the measurement of thermal conductivity using current techniques faces obstacles due to the low temperature gradient both in plane and across the interface in the sam…

Date of feed: Tue, 23 Jan 2024 04:17:05 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) **Multiplicative topological semimetals**

Adipta Pal, Joe H. Winter, and Ashley M. Cook

Author(s): Adipta Pal, Joe H. Winter, and Ashley M. Cook

[Phys. Rev. B 109, 035147] Published Mon Jan 22, 2024

**Higher-order double-Weyl semimetal**

Baoru Pan, Yuzhong Hu, Pan Zhou, Huaping Xiao, Xuejuan Yang, and Lizhong Sun

Author(s): Baoru Pan, Yuzhong Hu, Pan Zhou, Huaping Xiao, Xuejuan Yang, and Lizhong Sun

[Phys. Rev. B 109, 035148] Published Mon Jan 22, 2024

**Chern numbers for the two-body Hofstadter-Hubbard butterfly**

D. C. Alyuruk and M. Iskin

Author(s): D. C. Alyuruk and M. Iskin

[Phys. Rev. B 109, 035149] Published Mon Jan 22, 2024

**Fermi surface nesting and topological and magnetoresistance properties of $\mathrm{Th}{X}_{2} (X=\mathrm{As},\mathrm{Sb},\mathrm{Bi})$**

Sushree Sarita Sahoo, Ty M. Mason, Stephen B. Dugdale, and V. Kanchana

Author(s): Sushree Sarita Sahoo, Ty M. Mason, Stephen B. Dugdale, and V. Kanchana

[Phys. Rev. B 109, 035151] Published Mon Jan 22, 2024

**Composite-fermion pairing at half-filled and quarter-filled lowest Landau level**

Anirban Sharma, Ajit C. Balram, and J. K. Jain

Author(s): Anirban Sharma, Ajit C. Balram, and J. K. Jain

[Phys. Rev. B 109, 035306] Published Mon Jan 22, 2024

**Robust Majorana bound states in magnetic topological insulator nanoribbons with fragile chiral edge channels**

Declan Burke, Dennis Heffels, Kristof Moors, Peter Schüffelgen, Detlev Grützmacher, and Malcolm R. Connolly

Author(s): Declan Burke, Dennis Heffels, Kristof Moors, Peter Schüffelgen, Detlev Grützmacher, and Malcolm R. Connolly

[Phys. Rev. B 109, 045138] Published Mon Jan 22, 2024

**Quasiperiodic gallium adlayer on $i$-Al-Pd-Mn**

Pramod Bhakuni, Marian Krajčí, and Sudipta Roy Barman

Author(s): Pramod Bhakuni, Marian Krajčí, and Sudipta Roy Barman

[Phys. Rev. B 109, 045427] Published Mon Jan 22, 2024

**Simultaneous measurement of in-plane and interfacial thermal conductivity of isotopically labeled bilayer graphene**

Yang Zhang, Qiancheng Ren, Jiayuan Fang, Jinglan Liu, Suhao Wang, Jizhou Song, and Pei Zhao

Author(s): Yang Zhang, Qiancheng Ren, Jiayuan Fang, Jinglan Liu, Suhao Wang, Jizhou Song, and Pei Zhao

[Phys. Rev. B 109, L041407] Published Mon Jan 22, 2024

Found 1 papers in prl Bound states in the continuum (BICs), which are spatially localized states with energies lying in the continuum of extended modes, have been widely investigated in both quantum and classical systems. Recently, the combination of topological band theory with BICs has led to the creation of topologica…

Date of feed: Tue, 23 Jan 2024 04:17:03 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) **Non-Abelian Topological Bound States in the Continuum**

Long Qian, Weixuan Zhang, Houjuan Sun, and Xiangdong Zhang

Author(s): Long Qian, Weixuan Zhang, Houjuan Sun, and Xiangdong Zhang

[Phys. Rev. Lett. 132, 046601] Published Mon Jan 22, 2024

Found 1 papers in pr_res When nonadsorbing ring polymers are added in a fluid suspension of big, spherical colloids, solid gels are formed. Joint experimental, computational, and theoretical work shows that these gels are much stronger than those formed by the addition of linear polymer chains.

Date of feed: Tue, 23 Jan 2024 04:17:03 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) **Colloidal gelation induced by ring polymers**

Esmaeel Moghimi, Iurii Chubak, Maria Kaliva, Parvin Kiany, Taihyun Chang, Junyoung Ahn, Nikolaos Patelis, Georgios Sakellariou, Sergei A. Egorov, Dimitris Vlassopoulos, and Christos N. Likos

Author(s): Esmaeel Moghimi, Iurii Chubak, Maria Kaliva, Parvin Kiany, Taihyun Chang, Junyoung Ahn, Nikolaos Patelis, Georgios Sakellariou, Sergei A. Egorov, Dimitris Vlassopoulos, and Christos N. Likos

[Phys. Rev. Research 6, 013079] Published Mon Jan 22, 2024

Found 1 papers in acs-nano

Date of feed: Mon, 22 Jan 2024 14:03:11 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] Enhancing Solar-Driven Water Purification by Multiscale Biomimetic Evaporators Featuring Lamellar MoS2/GO Heterojunctions**

Haotian Zheng, Jiahui Fan, Aiying Chen, Xiang Li, Xiaofeng Xie, Yong Liu, and Zhiyi DingACS NanoDOI: 10.1021/acsnano.3c08648

Found 3 papers in comm-phys Communications Physics, Published online: 20 January 2024; doi:10.1038/s42005-024-01523-x Communications Physics, Published online: 17 January 2024; doi:10.1038/s42005-024-01525-9 Communications Physics, Published online: 15 January 2024; doi:10.1038/s42005-023-01485-6**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) **Strain-tunable Dirac semimetal phase transition and emergent superconductivity in a borophane**

Peng Yu

**Metasurface-based perfect vortex beam for optical eraser**

Shao-Yang Huang

**Observation of large spin-polarized Fermi surface of a magnetically proximitized semiconductor quantum well**

Masaaki Tanaka