Found 57 papers in cond-mat The bulk-boundary correspondence (BBC) relates in-gap boundary modes to bulk
topological invariants. In certain non-Hermitian topological systems,
conventional BBC becomes invalid in the presence of the non-Hermitian skin
effect (NHSE), which manifests as distinct energy spectra under the periodic
and open boundary conditions and massive eigenstate localization at boundaries.
In this work, we introduce a scheme to induce NHSE without breaking
conventional BBC, dubbed as the topologically compatible NHSE (TC-NHSE). In a
general one dimensional two-band model, we unveil two types of TC-NHSE that do
not alter topological phase transition points under any circumstance or only in
a certain parameter regime, respectively. Extending our model into two
dimension, we find that TC-NHSE can be selectively compatible to different sets
of Weyl points between different bands of the resultant semimetallic system,
turning some of them into bulk Fermi arcs while keeping the rest unchanged. Our
work hence helps clarify the intricate interplay between topology and NHSE in
non-Hermitian systems, and provides a versatile approach for designing
non-Hermitian topological systems where topological properties and NHSE do not
interfere each other.
Multivariate Bessel processes, otherwise known as radial Dunkl processes, are
stochastic processes defined in a Weyl chamber that are repelled from the
latter's boundary by a singular drift with a strength given by the multiplicity
function $k$. It is a well-known fact that when $k$ is sufficiently small,
these processes hit the Weyl chamber's boundary almost surely, and it was
recently shown by the authors that the collision times for the process of type
$A$, also known as the Dyson model (a one-dimensional multiple-particle
stochastic system), have a Hausdorff dimension that depends on $k$. In this
paper, we use the square of the alternating polynomial, which corresponds to
the reflection group of the process, to extend this result to all multivariate
Bessel processes of rational type, and we show that the Hausdorff dimension of
collision times is a piecewise-linear function of the minimum of $k$, but is
independent of the dimension of the space where the process lives. This implies
that the Hausdorff dimension is independent of the particle number for
processes with a particle system representation.
Nonlinear optics lies at the heart of classical and quantum light generation.
The invention of periodic poling revolutionized nonlinear optics and its
commercial applications by enabling robust quasi-phase-matching in crystals
such as lithium niobate. Here we realize a periodically poled van der Waals
semiconductor (3R-MoS$_2$). Due to its exceptional nonlinearity, we achieve
macroscopic frequency conversion efficiency over a microscopic thickness of
only $\SI{1.2}{\micro m}$, $100\times$ thinner than current systems with
similar performances. Due to unique intrinsic cavity effects, the
thickness-dependent quasi-phase-matched second harmonic signal surpasses the
usual quadratic enhancement by 50\%. Further, we report the broadband
generation of photon pairs at telecom wavelengths via quasi-phase-matched
spontaneous parametric down-conversion. Periodically poled microscopic crystals
may unlock on-chip entangled photon-pair sources for integrated quantum
circuitry and sensing.
We explore the edge properties of rectangular graphene nanoribbons featuring
two zigzag edges and two armchair edges. Although the self-consistent
Hartree-Fock fields break chiral symmetry, our work demonstrates that graphene
nanoribbons maintain their status as short-range entangled symmetry-protected
topological insulators. The relevant symmetry involves combined mirror and
time-reversal operations. In undoped ribbons displaying edge ferromagnetism,
the band gap edge states with a topological charge form on the zigzag edges. An
analysis of the anomalous continuity equation elucidates that this topological
charge is induced by the gap term. In low-doped zigzag ribbons, where the
ground state exhibits edge spin density waves, this topological charge appears
as a nearly zero-energy edge mode.
Phase transitions with lowering temperature is a manifestation of decreased
entropy and within the Landau theoretical framework these are accompanied by
the symmetry breaking. Whenever a symmetry is broken weakly or strongly, it
leaves its trail and the same may be captured indirectly using renormalization
of the quasi-particle excitations. Cr2Ge2Te6, a quasi-two-dimensional magnetic
material, provides a rich playground to probe dynamics of the quasi-particle
excitations as well as multiple phase transitions with lowering temperature
intimately linked with the lattice and spin degrees of freedom. Here, we report
in-depth inelastic light scattering measurements on single crystals of
Cr2Ge2Te6 as a function of temperature, from 6 K to 330 K, and polarization.
Our measurements reveal the long as well as short range ordering of the spins
below Tc (~ 60 K) and T* (~ 180 K), respectively; setting the stage for broken
rotational and time reversal symmetry, gauged via the distinct renormalization
of the phonon self-energy parameters along with the modes intensity. Our
measurements also uncovered an intriguing dependence of the interaction
strength between discrete state (phonon here) and the underlying continuum,
quantified using the Fano asymmetry parameter, as a function of the scattered
light polarization. Our results suggest the possibility of tuning the
interaction strength using controlled scattered light and symmetry in this 2D
magnet.
We performed metadynamics Monte Carlo simulations to obtain the free energy
as a function of the topological charge in the skyrmion-hosting magnetic model
systems (Pt$_{0.95}$Ir$_{0.05}$)/Fe/Pd(111) and Pd/Fe/Ir(111), using a spin
model containing parameters based on ab initio calculations. Using the
topological charge as collective variable, this method allows for evaluating
the temperature dependence of the number of skyrmionic quasiparticles. In
addition, from the free-energy cost of increasing and decreasing the
topological charge of the system we determined chemical potentials as a
function of the temperature. At lower temperature, the chemical potential for
creating skyrmions and antiskyrmions from the topologically trivial state is
different. This splitting of the chemical potential is particularly pronounced
for large external magnetic fields when the system is in a field-polarized
phase. We observed a change in the shape of the free-energy curves when
skyrmion-skyrmion interactions become more pronounced.
Topological interfaces of two-dimensional conformal field theories contain
information about symmetries of the theory and exhibit striking spectral and
entanglement characteristics. While lattice realizations of these interfaces
have been proposed for unitary minimal models, the same has remained elusive
for the paradigmatic Luttinger liquid {\it i.e.,} the free, compact boson
model. Here, we show that a topological interface of two Luttinger liquids can
be realized by coupling special one-dimensional superconductors. The gapless
excitations in the latter carry charges that are specific integer multiples of
the charge of Cooper-pairs. The aforementioned integers are determined by the
windings in the target space of the bosonic fields -- a crucial element
required to give rise to nontrivial topological interfaces. The latter occur
due to the perfect transmission of certain number of Cooper-pairs across the
interface. The topological interfaces arise naturally in Josephson junction
arrays with the simplest case being realized by an array of
experimentally-demonstrated~$0-\pi$ qubits, capacitors and ordinary Josephson
junctions. Signatures of the topological interface are obtained through
entanglement entropy computations. In particular, the subleading contribution
to the so-called interface entropy is shown to differ from existing field
theory predictions. The proposed lattice model provides an
experimentally-realizable alternative to spin and anyon chains for the analysis
of several conjectured conformal fixed points which have so far eluded
ab-initio investigation.
The two-dimensional electron gas (2DEG) at oxide interfaces exhibits various
exotic properties stemming from interfacial inversion symmetry breaking. In
this work, we report the emergence of large nonlinear Hall effects (NHE) in the
LaAlO3/KTaO3(111) interface 2DEG under zero magnetic field. Skew scattering was
identified as the dominant origin based on the cubic scaling of nonlinear Hall
conductivity with longitudinal conductivity and the threefold symmetry.
Moreover, a gate-tunable NHE with pronounced peak and dip was observed and
reproduced by our theoretical calculation. These results indicate the presence
of Berry curvature hotspots and thus a large Berry curvature triple at the
oxide interface. Our theoretical calculations confirm the existence of large
Berry curvatures from the avoided crossing of multiple 5d-orbit bands, orders
of magnitude larger than that in transition-metal dichalcogenides. NHE offers a
new pathway to probe the Berry curvature at oxide interfaces, and facilitates
new applications in oxide nonlinear electronics.
Graphene/hBN/graphene tunnel devices offer promise as sensitive mid-infrared
photodetectors but the microscopic origin underlying the photoresponse in them
remains elusive. In this work, we investigated the photocurrent generation in
graphene/hBN/graphene tunnel structures with localized defect states under
mid-IR illumination. We demonstrate that the photocurrent in these devices is
proportional to the second derivative of the tunnel current with respect to the
bias voltage, peaking during tunneling through the hBN impurity level. We
revealed that the origin of the photocurrent generation lies in the change of
the tunneling probability upon radiation-induced electron heating in graphene
layers, in agreement with the theoretical model that we developed. Finally, we
show that at a finite bias voltage, the photocurrent is proportional to the
either of the graphene layers heating under the illumination, while at zero
bias, it is proportional to the heating difference. Thus, the photocurrent in
such devices can be used for accurate measurements of the electronic
temperature providing a convenient alternative to Johnson noise thermometry.
We present a theoretical investigation on the pressure-induced emergence of
Dirac semimetallic properties in the XCdP (X = Na, K) materials, employing
first-principles calculations. Dirac semimetals, characterized by linear
dispersion relations in their electronic band structures, have gained
prominence due to their unique topological features and potential applications
in electronic devices. Through systematic calculations, we explore the
electronic structure evolution of NaCdP and KCdP under varying pressure
conditions. Our findings reveal a compelling transition to a Dirac semimetallic
state in both NaCdP and KCdP under applied pressure. The electronic band
structures exhibit distinct Dirac cones at the Fermi level, indicating the
presence of massless Dirac fermions. Moreover, the pressure-induced Dirac
semi-metallic phase in these compounds are found to be robust, and are
protected by crystal symmetry. We provide a comprehensive analysis of the
bandgap, Fermi surface, and other relevant electronic properties, offering
insights into the pressure-driven phase transition in NaCdP and KCdP. The
tunability of these materials under external pressure suggests their potential
utility in next-generation electronic devices and quantum technologies.
The primary obstacle in the field of quantum thermodynamics revolves around
the development and practical implementation of quantum heat engines operating
at the nanoscale. One of the key challenges associated with quantum working
bodies is the occurrence of "quantum friction," which refers to irreversible
wasted work resulting from quantum inter-level transitions. Consequently, the
construction of a reversible quantum cycle necessitates the utilization of
adiabatic shortcuts. However, the experimental realization of such shortcuts
for realistic quantum substances is exceedingly complex and often unattainable.
In this study, we propose a quantum heat engine that capitalizes on the
plasmonic skyrmion lattice. Through rigorous analysis, we demonstrate that the
quantum skyrmion substance, owing to its topological protection, exhibits zero
irreversible work. Consequently, our engine operates without the need for
adiabatic shortcuts. We checked by numerical calculations and observed that
when the system is in the quantum skyrmion phase, the propagated states differ
from the initial states only by the geometricl and dynamical phases. The
adiabacit evoluation leads to the zero transition matrix elements and zero
irreversible work. By employing plasmonic mods and an electric field, we drive
the quantum cycle. The fundamental building blocks for constructing the quantum
working body are individual skyrmions within the plasmonic lattice. As a
result, one can precisely control the output power of the engine and the
thermodynamic work accomplished by manipulating the number of quantum skyrmions
present.
We consider electronic spectra of graphene nanotubes and their perturbation
by impurity atoms absorbed at different positions on nanotube surfaces, within
the framework of Anderson hybrid model. A special attention is given to the
cases when Dirac-like 1D modes appear in the nanotube spectrum and their
hybridization with localized impurity states produces, at growing impurity
concentration $c$, onset of a mobility gap near the impurity level and even
opening, at yet higher $c$, of some narrow delocalized range within this
mobility gap. Such behaviors are compared with the similar effects in the
previously studied 2D graphene and armchair type graphene nanoribbons. Some
possible practical applications are discussed.
The topology between Bloch states in reciprocal space has attracted
tremendous attention in recent years. The quantum geometry of the band
structure is composed of quantum metric as real part and berry curvature as
imaginary part. While the Berry curvature, the Berry curvature dipole and Berry
connection polarizability have been recently revealed by the first order
anomalous hall, second order and third order nonlinear Hall effect
respectively, the quantum metric induced second order nonlinear transverse and
longitudinal response in topological antiferromagnetic material MnBi2Te4 was
only very recently reported. Here we demonstrate the similar third order
nonlinear transport properties in the topological antiferromagnetic CoNb3S6. We
observed that the third order nonlinear longitudinal V3{\omega} xx increase
significantly at the antiferromagnetic transition temperature TN ~ 29 K, which
was probably induced by the quantum metric without time-reversal symmetry or
inversion symmetry. Besides, temperature-dependent nonlinear behaviour was
observed in the first order I-V curve below the Neel temperature TN, which was
not reported in MnBi2Te4 and FeSn. Such nonlinear I-V behaviour hints for the
possible existence of Charge Density Wave (CDW) state, which has been
discovered in its sister material FeNb3S6. Simultaneously, two plateaus in the
third order nonlinear longitudinal V3{\omega} xx~ I^{\omega} curve are
observed, which is also speculated to be related with the possible CDW state.
However, the genuine mechanism for the first order nonlinear I-V and its
relation with the third order nonlinear transport call for more experimental
investigations and theoretical interpretation. Our work provides a way to
explore third harmonic nonlinear transport and interaction with magnetic order
and CDW.
Attaining viable thermoelectric cooling at cryogenic temperatures is of major
fundamental and technological interest for novel electronics and quantum
materials applications. In-device temperature control can provide a more
efficient and precise thermal environment management as compared to the
conventional global cooling. Here we develop nanoscale cryogenic imaging of a
magneto-thermoelectric effect and demonstrate absolute cooling and an ultrahigh
Ettingshausen effect in exfoliated WTe2 Weyl semimetal flakes at liquid He
temperatures. Application of a current and perpendicular magnetic field gives
rise to cooling via generation of electron-hole pairs on one side of the sample
and heating by their recombination at the opposite side. In contrast to bulk
materials, the cooling process is found to be nonmonotonic in magnetic field
and device size. The derived model of magneto-thermoelectricity in mesoscopic
semimetal devices shows that the cooling efficiency and the induced temperature
profiles are governed by the interplay between sample geometry, electron-hole
recombination length, magnetic field, and flake and substrate heat
conductivities. The findings open the way for direct integration of microscopic
thermoelectric cooling and for temperature landscape engineering in novel van
der Waals devices.
The thermoelectric properties of armchair graphene nanoribbons (AGNRs) with
array characteristics are investigated theoretically using the tight-binding
model and Green's function technique. The AGNR structures with array
characteristics are created by embedding a narrow boron nitride nanoribbon
(BNNR) into a wider AGNR, resulting in two narrow AGNRs. This system is denoted
as w-AGNR/n-BNNR, where 'w' and 'n' represent the widths of the wider AGNR and
narrow BNNR, respectively. We elucidate the coupling effect between two narrow
symmetrical AGNRs on the electronic structure of w-AGNR/n-BNNR. A notable
discovery is that the power factor of the 15-AGNR/5-BNNR with the minimum width
surpasses the quantum limitation of power factor for 1D ideal systems. The
energy level degeneracy observed in the first subbands of w-AGNR/n-BNNR
structures proves to be highly advantageous in enhancing the electrical power
outputs of graphene nanoribbon devices.
Skyrmions are spin-swirling textures hosting wonderful properties with
potential implications in information technology. Such magnetic particles carry
a magnetization, whose amplitude is crucial to establish them as robust
magnetic bits, while their topological nature gives rise to a plethora of
exquisite features such as topological protection, the skyrmion and topological
Hall effects as well as the topological orbital moment. These effects are all
induced by an emergent magnetic field directly proportional to the three-spin
scalar chirality, $\chi= (\mathbf{S}_i\times\mathbf{S}_j)\cdot \mathbf{S}_k$,
and shaped by the peculiar spatial dependence of the magnetization. Here, we
demonstrate the existence of novel chiral magnetizations emerging from the
interplay of spin-orbit interaction and either $\chi$ or the two-spin vector
chirality $\boldsymbol{\kappa} = \mathbf{S}_i\times\mathbf{S}_j$. By
scrutinizing correlations among the spin, orbital (trivial and chiral)
magnetizations, we unveil from ab-initio universal patterns, quantify the rich
set of magnetizations carried by single skyrmions generated in PdFe bilayer on
Ir(111) surface and demonstrate the ability to engineer their magnitude via
controlled implantation of impurities. We anticipate that our findings can
guide the design of disruptive storage devices based on skyrmionic bits by
encoding the desired magnetization with strategic seeding of defects.
Negative magnetoresistance (NMR) is a marked feature of Dirac semimetals, and
may be caused by multiple mechanisms, such as the chiral anomaly, the Zeeman
energy, the quantum interference effect, and the orbital moment. Recently, an
experiment on Dirac semimetal Cd$_3$As$_2$ thin films revealed a new NMR
feature that depends strongly on the thickness of the sample [T. Schumann,
\emph{et al}., Phys. Rev. B 95, 241113(R) (2017)]. Here, we introduce a new
mechanism of inducing NMR via the presence of the van Hove singularity (VHS) in
the density of states. Theoretical fitting of the experimental data on
magnetoconductivity and magnetoresistance shows good agreement, indicating that
the observed NMR in thin films of Cd$_3$As$_2$ can be attributed to the VHS.
This work provides new insights into the underlying of Dirac semimetals.
Collective plasmon modes, riding on top of drifting electrons, acquire a
fascinating nonreciprocal dispersion characterized by $\omega_p(\bm{q}) \neq
\omega_p(-\bm{q})$. The {\it classical} plasmonic Doppler shift arises from the
polarization of the Fermi surface due to the applied DC bias voltage. Going
beyond this paradigm, we predict a {\it quantum} plasmonic Doppler shift
originating from the quantum metric of the Bloch wavefunction. We
systematically compare the classical and quantum Doppler shifts by
investigating the drift-induced nonreciprocal plasmon dispersion in generic
quantum systems. We demonstrate quantum nonreciprocal plasmons in graphene and
twisted bilayer graphene. We show that the quantum plasmonic Doppler shift
dominates in \moire systems at large wavevectors, yielding plasmonic
nonreciprocity up to 20\% in twisted bilayer graphene. Our findings demonstrate
the supremacy of plasmonic quantum Doppler shift in \moire systems, motivating
the design of innovative nonreciprocal photonic devices with potential
technological implications.
Heat transport in two-dimensions is fundamentally different from that in
three dimensions. As a consequence, the thermal properties of 2D materials are
of great interest, both from scientific and application point of view. However,
few techniques are available for accurate determination of these properties in
ultrathin suspended membranes. Here, we present an optomechanical methodology
for extracting the thermal expansion coefficient, specific heat and thermal
conductivity of ultrathin membranes made of 2H-TaS2, FePS3, polycrystalline
silicon, MoS2 and WSe2. The obtained thermal properties are in good agreement
with values reported in the literature for the same materials. Our work
provides an optomechanical method for determining thermal properties of
ultrathin suspended membranes, that are difficult to measure otherwise. It can
does provide a route towards improving our understanding of heat transport in
the 2D limit and facilitates engineering of 2D structures with dedicated
thermal performance.
In recent years, the investigation of novel materials for various
technological applications has gained much importance in materials science
research. Tri-molybdenum phosphide (Mo3P), a promising transition metal
phosphide (TMP), has gathered significant attention due to its unique
structural and electronic properties, which already make it potentially
valuable system for catalytic and electronic device applications. Through an
in-depth study using the density functional theory (DFT) calculations, this
work aims to clarify the basic properties of the Mo3P compound at different
pressures. In this work, we have studied the structural, elastic,
optoelectronic and thermophysical properties of binary Mo3P compound. In this
investigation, we varied uniform hydrostatic pressure from 0 GPa to 30 GPa. A
complete geometrical optimization for structural parameters is performed and
the obtained values are in good accord with the experimental values where
available. It is also found that Mo3P possesses very low level of elastic
anisotropy, reasonably good machinability, ductile nature, relatively high
Vickers hardness, high Debye temperature and high melting temperature.
Thermomechanical properties indicate that the compound has potential to be used
as a thermal barrier coating material. The bonding nature in Mo3P has been
explored. The electronic band structure shows that Mo3P has no band gap and
exhibits conventional metallic behavior. All of the energy dependent optical
characteristics demonstrate apparent metallic behavior and agree exactly with
the electronic density of states calculations. The compound has excellent
reflective and absorptive properties suitable for optical applications.
Pressure dependent variations of the physical properties are explored and their
possible link with superconductivity has been discussed.
Tunable photovoltaic photodetectors are of significant relevance in the
fields of programmable and neuromorphic optoelectronics. However, their
widespread adoption is hindered by intricate architectural design and energy
consumption challenges. This study employs a nonvolatile MoTe2/hBN/graphene
semi-floating photodetector to address these issues. Programed with pulsed gate
voltage, the MoTe2 channel can be reconfigured from an n+-n to a p-n
homojunction, and the photocurrent transition changes from negative to positive
values. Scanning photocurrent mapping reveals that the negative and positive
photocurrents are attributed to Schottky junction and p-n homojunction,
respectively. In the p-n configuration, the device demonstrates self-driven,
linear, rapid response (~3 ms), and broadband sensitivity (from 405 to 1500 nm)
for photodetection, with typical performances of responsivity at ~0.5 A/W and
detectivity ~1.6*10^12 Jones under 635 nm illumination. These outstanding
photodetection capabilities emphasize the potential of the semi-floating
photodetector as a pioneering approach for advancing logical and nonvolatile
optoelectronics.
Two-dimensional (2D) material photodetectors have gained great attention as
potential elements for optoelectronic applications. However, the linearity of
the photoresponse is often compromised by the carrier interaction, even in 2D
photodiodes. In this study, we present a new device concept of dual-floating
van der Waals heterostructures (vdWHs) photodiode by employing ambipolar MoTe2
and n-type MoS2 2D semiconductors. The presence of type II heterojunctions on
both sides of channel layers effectively deplete carriers and restrict the
photocarrier trapping within the channel layers. As a result, the device
exhibits robust linear photoresponse under photovoltaic mode from the visible
(405 nm) to near-infrared (1600 nm) band. With the built-in electric field of
the vdWHs, we achieve a linear dynamic range of ~ 100 dB, responsivity of ~
1.57 A/W, detectivity of ~ 4.28 * 10^11 Jones, and response speed of ~ 30
{\mu}s. Our results showcase a promising device concept with excellent
linearity towards fast and low-loss detection, high-resolution imaging, and
logic optoelectronics.
Understanding the interplay between electronic interactions and
disorder-induced localization has been a longstanding quest in the physics of
quantum materials. One of the most convincing demonstrations of the scaling
theory of localization for noninteracting electrons has come from plateau
transitions in the integer quantum Hall effect with short-range disorder,
wherein the localization length diverges as the critical filling factor is
approached with a measured scaling exponent close to the theoretical estimates.
In this work, we extend this physics to the fractional quantum Hall effect, a
paradigmatic phenomenon arising from a confluence of interaction, disorder, and
topology. We employ high-mobility trilayer graphene devices where the transport
is dominated by short-range impurity scattering, and the extent of Landau level
mixing can be varied by a perpendicular electric field. Our principal finding
is that the plateau-to-plateau transitions from N+1/3 to N+2/5 and from N+2/5
to N+3/7 fractional states are governed by a universal scaling exponent, which
is identical to that for the integer plateau transitions and is independent of
the perpendicular electric field. These observations and the values of the
critical filling factors are consistent with a description in terms of Anderson
localization-delocalization transitions of weakly interacting electron-flux
bound states called composite Fermions. This points to a universal effective
physics underlying fractional and integer plateau-to-plateau transitions
independent of the quasiparticle statistics of the phases and unaffected by
weak Landau level mixing. Besides clarifying the conditions for the realization
of the scaling regime for composite fermions, the work opens the possibility of
exploring a wide variety of plateau transitions realized in graphene, including
the fractional anomalous Hall phases and non-abelian FQH states.
Ferroelectric fluorite oxides like hafnium (HfO2)-based materials are
considered to be one of the most potential candidates for nowadays large-scale
integrated-circuits owing to their high compatibility with silicon-based
technology. While zirconia (ZrO2)-based fluorites materials, which holds the
same fluorite structure, is usually thought to be anti- or week ferroelectric.
Our study demonstrates a giant ferroelectric remanent polarization (Pr)
amounted to 53 uC/cm2 in orthorhombic ZrO2 growing on (110) SrTiO3, which is
comparable to those most outstanding HfO2-based materials. We believe this
giant remanent polarization stems from the irreversible
anti-ferroelectric-to-ferroelectric (AFE-to-FE) phase transition activated by
electric field, which converts the as-grown anti-ferroelectric-ferroelectric
blends into purely ferroelectric ZrO2. Our study reverses the poor
ferroelectric opinion on ZrO2 by promoting the Pr to the best HfO2-based
materials level.
We predict here the fine structure of an electrically tunable negatively
charged exciton (trion) composed of two electrons and a hole confined in a
gated bilayer graphene quantum dot (QD). We start with an atomistic approach,
allowing us to compute confined electron and confined hole QD states for a
structure containing over one million atoms. Using atomistic wavefunctions we
compute Coulomb matrix elements and self-energies. In the next step, by solving
the Bethe-Salpeter-like equation for trions, we describe a negatively charged
exciton, built as a strongly interacting interlayer complex of two electrons in
the conduction band and one hole in the valence band. Unlike in conventional
semiconducting QDs, we show that the trion contains a fine structure composed
of ten states arising from the valley and spin degrees of freedom. Finally, we
obtain absorption into and emission from the trion states. We predict the
existence of bright low-energy states and propose to extract the fine structure
of the trion using the temperature dependence of emission spectra.
We investigate the long-range behavior and size dependence of the
Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in hexagonal and triangular
graphene nanoflakes with zigzag and arm-chair edges. We employ the
tight-binding model with exact diagonalization to calculate the RKKY
interaction as a function of the distance between magnetic impurities,
nanoflake size, and edge geometry. Our findings demonstrate a strong dependency
of the RKKY interaction on edge geometry and flake size, with notable changes
in the RKKY interaction strength. We further analyze the influence of
structural defects on the interaction strength of exchange interactions.
Landau theory's implicit assumption that microscopic details cannot affect
the system's phases has been challenged only recently in systems such as
antiferromagnetic quantum spin chains with periodic boundary conditions, where
topological frustration can be induced. In this work, we show that the latter
modifies the zero temperature phase diagram of the XY chain in a transverse
magnetic field by inducing new quantum phase transitions. In doing so, we come
across the first case of second order boundary quantum phase transition
characterized by a quartic dispersion relation. Our analytical results are
supported by numerical investigations and lay the foundation for understanding
the phase diagram of this frustrated model.
Here, using low-temperature optical scanning tunneling microscopy (STM), we
investigate inelastic light scattering (ILS) in the vicinity of a single-atom
quantum point contact (QPC). A vibration mode localized at the single Ag adatom
on the Ag(111) surface is resolved in the ILS spectrum, resulting from
tip-enhanced Raman scattering (TERS) by the atomically-confined plasmonic field
in the STM junction. Furthermore, we trace how TERS from the single adatom
evolves as a function of the gap distance. The exceptional stability of the
low-temperature STM allows to examine distinctly different electron transport
regimes of the picocavity, namely in the tunneling and quantum point contact
(QPC) regimes. This measurement shows that the vibration mode localized at the
adatom and its TERS intensity exhibits a sharp change upon the QPC formation,
indicating that the atomic-level structure has a crucial impact on the
plasmonic properties. To gain microscopic insights into picocavity
optomechanics, we scrutinize the structure and plasmonic field in the STM
junction using time-dependent density functional theory. The simulations reveal
that atomic-scale structural relaxation at the single-atom QPC results in a
discrete change of the plasmonic field strength, volume, and distribution as
well as the vibration mode localized at the single atom. These findings give a
qualitative explanation for the experimental observations. Furthermore, we
demonstrate that strong ILS is a characteristic feature of QPC by continuously
forming, breaking, and reforming the atomic contact, and how the plasmonic
resonance evolves throughout the non-tunneling, tunneling, and QPC regimes.
We present a comprehensive first-principles study on the optoelectronic
properties of the single-layer nickel diazenide (penta-NiN$_2$), a recently
synthesized Cairo pentagonal 2D semiconductor. We carry out $ab$ $initio$
calculations based on the density-functional theory (DFT) and many-body
perturbation theory, within the framework of Green's functions, to describe the
quasiparticle properties and analyze the excitonic effects on the optical
properties of monolayer penta-NiN$_2$. Our results reveal a quasiparticle band
gap of approximately 1 eV within the eigenvalue self-consistent $GW$ approach,
corroborating the monolayer penta-NiN$_2$'s potential in optoelectronics.
Remarkably, the acoustic phonon-limited carrier mobility for the monolayer
penta-NiN$_2$ exhibits an ultra-high hole mobility of $84{\times}10^4$
cm$^2$/V$\cdot$s. Furthermore, our findings indicate that the material's band
gap exhibits an anomalous negative dependence on temperature. Despite being a
two-dimensional material, monolayer penta-NiN$_2$ presents resonant excitons in
its most prominent absorption peak. Therefore, penta-NiN$_2$ boasts compelling
and promising properties that merit exploration in optoelectronics and
high-speed devices.
Exotic quantum solids can host electronic states that spontaneously break
rotational symmetry of the electronic structure, such as electronic nematic
phases and unidirectional charge density waves (CDWs). When electrons couple to
the lattice, uniaxial strain can be used to anchor and control this electronic
directionality. Here we reveal an unusual impact of strain on unidirectional
"smectic" CDW orders in kagome superconductors AV3Sb5 using
spectroscopic-imaging scanning tunneling microscopy. We discover local
decoupling between the smectic electronic director axis and the direction of
anisotropic strain. While the two are generally aligned along the same
direction in regions of small CDW gap, the two become misaligned in regions
where CDW gap is the largest. This in turn suggests nanoscale variations in
smectic susceptibility, which we attribute to a combination of local strain and
electron correlation strength. Overall, we observe an unusually high decoupling
rate between the smectic electronic director of the 3-state Potts order and
anisotropic strain, revealing weak smecto-elastic coupling in the CDW phase of
kagome superconductors. This is phenomenologically different from the
extensively studied nemato-elastic coupling in the Ising nematic phase of
Fe-based superconductors, providing a contrasting picture of how strain can
control electronic unidirectionality in different families of quantum
materials.
The hydrodynamic behavior of electron fluids in a certain range of
temperatures and densities is well established in graphene and in 2D
semiconductor heterostructures. The hydrodynamic regime is intrinsically based
on electron-electron interactions, and therefore it provides a unique
opportunity to study electron correlations. Unfortunately, in all existing
measurements, the relative contribution of hydrodynamic effects to transport is
rather small. Viscous hydrodynamic effects are masked by impurities,
interaction with phonons, uncontrolled boundaries and ballistic effects. This
essentially limits the accuracy of measurements of electron viscosity.
Fundamentally, what causes viscous friction in the electron fluid is the
property of the flow called vorticity. In this paper, we propose to use
micromagnets to increase the vorticity by orders of magnitude. Experimental
realization of this proposal will bring electron hydrodynamics to a
qualitatively new precision level, as well as opening a new way to characterize
and externally control the electron fluid.
We derive the linearized Ginzburg-Landau (GL) equation for an ultra-thin
superconducting film with curvature in a magnetic field. By introducing a novel
transverse order parameter that varies slowly along the film, and applying the
superconducting/vacuum boundary condition, we decouple the linearized GL
equation into a transverse part and a surface part that includes the
superconducting geometric potential (GP). The nucleation of the superconducting
state in curved thin superconducting films can be equivalently described by the
surface part equation. In the equivalent GL free energy of a curved
superconducting film, the superconducting GP enables the film to remain in the
superconducting state even when the superconducting parameter $ \alpha $ turns
positive by further reducing the quadratic term of the order parameter.
Furthermore, we numerically investigate the phase transition of a rectangle
thin superconducting film bent around a cylindrical surface. Our numerical
results show that the superconducting GP enhances the superconductivity of the
curved film by weakening the effect of the magnetic field, and the increase of
the critical temperature, in units of the bulk critical temperature, is equal
to the product of the negative superconducting GP and the square of the
zero-temperature coherence length, which agrees with our theoretical
predictions.
Recently, a quantum anomalous Hall (QAH) state was observed in AB stacked
moir\'e MoTe$_2$/WSe$_2$ heterobilayers at half-filling. More recent
layer-resolved magnetic circular dichroism (MCD) measurements revealed that
spin-polarized moir\'e bands from both the MoTe$_2$ and the WSe$_2$ layers are
involved at the formation of the QAH state. This scenario is not expected by
existing theories. In this work, we suggest that the observed QAH state is a
new state of matter, namely, a topological $p_x+ip_y$ inter-valley coherent
state (TIVC). We point out that the massive Dirac spectrum of the MoTe$_2$
moir\'e bands, together with the Hund's interaction and the Coulomb
interactions give rise to this novel QAH state. Through a self-consistent
Hartree-Fock analysis, we find a wide range of interaction strengths and
displacement fields that the $p_x+ip_y$-pairing phase is energetically
favourable. Besides explaining several key features of the experiments, our
theory predicts that the order parameter would involve the pairing of electrons
and holes with a definite momentum mismatch such that the pairing would
generate a new unit cell which is three times the size of the original moir\'e
unit cell, due to the order parameter modulations.
We show that topological superconductivity can be generally induced in a
magnetic metal through the superconducting proximity effect. In this case, the
topological superconductivity originates from band degeneracies controlled by
crystalline symmetries. We demonstrate this general scheme in a model with a
4-fold band degeneracy protected by the space group P4=nmm. We show that first
order or second-order topological superconductivity can be realized in the
presence of a ferromagnetic order or an antiferromagnetic order respectively.
We derive the corresponding topological invariants and analyze Majorana modes.
Our study provides a general method to realize topological superconductivity
and help to identify new platforms to generate Majorana zero modes.
The action of any local operator on a quantum system propagates through the
system carrying the information of the operator. This is usually studied via
the out-of-time-order correlator (OTOC). We numerically study the information
propagation from one end of a periodically driven spin-1/2 $XY$ chain with open
boundary conditions using the Floquet infinite-temperature OTOC. We calculate
the OTOC for two different spin operators, $\sigma^x$ and $\sigma^z$. For
sinusoidal driving, the model can be shown to host different types of edge
states, namely, topological (Majorana) edge states and non-topological edge
states. We observe a localization of information at the edge for both
$\sigma^z$ and $\sigma^x$ OTOCs whenever edge states are present. In addition,
in the case of non-topological edge states, we see oscillations of the OTOC in
time near the edge, the oscillation period being inversely proportional to the
gap between the Floquet eigenvalues of the edge states. We provide an
analytical understanding of these effects due to the edge states. It was known
earlier that the OTOC for the spin operator which is local in terms of
Jordan-Wigner fermions ($\sigma^z$) shows no signature of information
scrambling inside the light cone of propagation, while the OTOC for the spin
operator which is non-local in terms of Jordan-Wigner fermions ($\sigma^x$)
shows signatures of scrambling. We report a remarkable `unscrambling effect' in
the $\sigma^x$ OTOC after reflections from the ends of the system. Finally, we
demonstrate that the information propagates into the system mainly via the bulk
states with the maximum value of the group velocity, and we show how this
velocity is controlled by the driving frequency and amplitude.
The magnetic and transport properties of BiFeO3/La2NiMnO6 (BFO/LNMO)
composite have been investigated both experimentally and theoretically. Unlike
the normal rhombohedral (R3c) phase, BFO in the composites is crystallized in
the triclinic phase (P1). Interestingly, the composites demonstrate a
significant enhancement in the magnetization, magnetoelectric coupling and show
higher resistivity than that of the regular BFO (R3c). As LNMO has its Curie
temperature at 280 K, the room temperature and above room temperature magnetic
contribution in the composites is expected to be from the triclinic BFO phase.
Experimentally observed enhancement in magnetization is validated using
classical Monte Carlo simulation and density functional theory (DFT)
calculations. The calculations reveal higher magnetic moments in triclinic BFO
as compared to the rhombohedral BFO. Overall, this study reveals triclinic BFO
as the promising room temperature multiferroic phase which is helpful to
optimize the multiferroicity of BFO and achieve wider applications in future.
In hybrid Josephson junctions with three or more superconducting terminals
coupled to a semiconducting region, Andreev bound states may form
unconventional energy band structures, or Andreev matter, which are engineered
by controlling superconducting phase differences. Here we report tunnelling
spectroscopy measurements of three-terminal Josephson junctions realised in an
InAs/Al heterostructure. The three terminals are connected to form two loops,
enabling independent control over two phase differences and access to a
synthetic Andreev band structure in the two-dimensional phase space. Our
results demonstrate a phase-controlled Andreev molecule, originating from two
discrete Andreev levels that spatially overlap and hybridise. Signatures of
hybridisation are observed in the form of avoided crossings in the spectrum and
band structure anisotropies in the phase space, all explained by a numerical
model. Future extensions of this work could focus on addressing spin-resolved
energy levels, ground state fermion parity transitions and Weyl bands in
multiterminal geometries.
The ground states of twisted bilayer graphene (TBG) at chiral and flat-band
limit with integer fillings are known from exact solutions, while their
dynamical and thermodynamical properties are revealed by unbiased quantum Monte
Carlo (QMC) simulations. However, to elucidate experimental observations of
correlated metallic, insulating and superconducting states and their
transitions, investigations on realistic, or non-chiral cases are vital. Here
we employ momentum-space QMC method to investigate the evolution of correlated
states in magic-angle TBG away from chiral limit at charge neutrality with
polarized spin/valley, which approximates to an experimental case with filling
factor $\nu=-3$. We find that the ground state evolves from quantum anomalous
Hall insulator into an intriguing correlated semi-metallic state possessing
heavy-fermion features as AA hopping strength reaches experimental values. Such
a state resembles the recently proposed heavy-fermion representations with
localized electrons residing at AA stacking regions and delocalized electrons
itinerating via AB/BA stacking regions. The spectral signatures of the
localized and itinerant electrons in the heavy-fermion semimetal phase are
revealed, with the connection to experimental results being discussed.
Atomic gases confined in curved geometries are characterized by distinctive
features that are absent in their flat counterparts, such as periodic
boundaries, local curvature, and nontrivial topologies. The recent experiments
with shell-shaped quantum gases and the study of ring-shaped superfluids point
out that the manifold of a quantum gas could soon become a controllable
feature, thus allowing to address the fundamental study of curved many-body
quantum systems. Here, we review the main geometries realized in the
experiments, analyzing the theoretical and experimental status on their phase
transitions and on the superfluid dynamics. In perspective, we delineate the
study of vortices, the few-body physics, and the search for analog models in
various curved geometries as the most promising research areas.
We explore the direct to indirect band gap transitions in MX$_2$ (M= Mo/W, X=
S/Se) transition metal dichalcogenides heterobilayers for different system
compositions, strains, and twist angles based on first principles density
functional theory calculations within the G$_0$W$_0$ approximation. The
obtained band gaps that typically range between 1.4$-$2.0 eV are
direct/indirect for different/same chalcogen atom systems and can often be
induced through expansive/compressive biaxial strains of a few percent. A
direct to indirect gap transition is verified for heterobilayers upon
application of a finite 16$^{\circ}$ twist that weakens interlayer coupling.
The large inter-layer exciton binding energies of the order of $\sim$~250~meV
estimated by solving the Bethe-Salpeter equation suggest these systems are
amenable to be studied through infrared and Raman spectroscopy.
We study the effect of various configurations of vacancies on the magnetic
properties of graphene nanoflake (GNF) with screened realistic long-range
electron interaction [T. O. Wehling, et. al., Phys. Rev. Lett. 106, 236805
(2011)] within the functional renormalization group approach. In agreement with
previous studies, the presence of vacancies in GNF yields to a strong
enhancement of spin-density-wave (SDW) correlations. We show however that only
some part of the considered configurations of vacancies posses SDW ground
state. The probability of a system with a random configuration of vacancies to
be in the SDW ground state increases with increase of vacancy concentration.
The disorder-averaged sublattice magnetization increases linearly with the
concentration of vacancies. The ratio of the sublattice magnetizations at the
center and edges of GNF, averaged over various realizations of disorder,
depends only weakly on the number of vacancies. The effects of vacancies on the
linear conductance and charge properties of GNF are discussed.
Interfacing magnetism with superconductivity gives rise to a wonderful
playground for intertwining key degrees of freedom: Cooper pairs, spin, charge,
and spin-orbit interaction, from which emerge a wealth of exciting phenomena,
fundamental in the nascent field of superconducting spinorbitronics and
topological quantum technologies. Magnetic exchange interactions (MEI), being
isotropic or chiral such as the Dzyaloshinskii-Moriya interactions (DMI), are
vital in establishing the magnetic behavior at these interfaces as well as in
dictating not only complex transport phenomena, but also the manifestation of
topologically trivial or non-trivial objects as skyrmions, spirals,
Yu-Shiba-Rusinov states and Majorana modes. Here, we propose a methodology
enabling the extraction of the tensor of MEI from electronic structure
simulations accounting for superconductivity. We apply our scheme to the case
of a Mn layer deposited on Nb(110) surface and explore proximity-induced impact
on the MEI. Tuning the superconducting order parameter, we unveil potential
change of the magnetic order accompanied with chirality switching. Owing to its
simple formulation, our methodology can be readily implemented in
state-of-the-art frameworks capable of tackling superconductivity and
magnetism. Our findings opens intriguing exploration paths, where chirality and
magnetism can be engineered depending on the conducting nature of
magneto-superconducting interfaces. We thus foresee implications in the
simulations and prediction of topological superconducting bits as well as in
cryogenic superconducting hybrid devices involving magnetic units.
We consider the Lifshitz topological transitions and the corresponding
changes in the galvanomagnetic properties of a metal from the point of view of
the general classification of open electron trajectories arising on Fermi
surfaces of arbitrary complexity in the presence of magnetic field. The
construction of such a classification is the content of the Novikov problem and
is based on the division of non-closed electron trajectories into topologically
regular and chaotic trajectories. The description of stable topologically
regular trajectories gives a basis for a complete classification of non-closed
trajectories on arbitrary Fermi surfaces and is connected with special
topological structures on these surfaces. Using this description, we describe
here the distinctive features of possible changes in the picture of electron
trajectories during the Lifshitz transitions, as well as changes in the
conductivity behavior in the presence of a strong magnetic field. As it turns
out, the use of such an approach makes it possible to describe not only the
changes associated with stable electron trajectories, but also the most general
changes of the conductivity diagram in strong magnetic fields.
We discuss the link between the quasielectron wavefunctions proposed by
Laughlin and by Jain and show both analytically and numerically that Laughlin's
quasielectron is a non-local composite fermion state. Composite-fermion states
are typically discussed in terms of the composite-fermion Landau levels (also
known as Lambda levels). In standard composite-fermion quasielectron
wavefunctions the excited Lambda levels have sub-extensive occupation numbers.
However, once the Laughlin's quasielectron is reformulated as a composite
fermion, an overall logarithmic occupation of the first Lambda level is made
apparent, which includes orbitals that are localized at the boundary of the
droplet. Even though the wavefunction proposed by Laughlin features a localised
quasielectron with well-defined fractional charge, it exhibits some non-trivial
boundary properties which motivate our interpretation of Laughlin's
quasielectron as a non-local object. This has an important physical
consequence: Laughlin's quasielectron fractionalizes an incorrect spin, deeply
related to the anyonic braiding statistics. We conclude that Laughlin's
quasielectron is not a good candidate for a quasielectron wavefunction.
Amid the growing interest in non-Hermitian quantum systems, non-interacting
models have received the most attention. Here, through the stochastic series
expansion quantum Monte Carlo method, we investigate non-Hermitian physics in
interacting quantum systems, e.g., various non-Hermitian quantum spin chains.
While calculations yield consistent numerical results under open boundary
conditions, non-Hermitian quantum systems under periodic boundary conditions
observe an unusual concentration of imaginary-time worldlines over nontrivial
winding and require enhanced ergodicity between winding-number sectors for
proper convergences. Such nontrivial worldline winding is an emergent physical
phenomenon that also exists in other non-Hermitian models and analytical
approaches. Alongside the non-Hermitian skin effect and the point-gap
spectroscopy, it largely extends the identification and analysis of
non-Hermitian topological phenomena to quantum systems with interactions,
finite temperatures, biorthogonal basis, and periodic boundary conditions in a
novel and controlled fashion. Finally, we study the direct physical
implications of such nontrivial worldline winding, which bring additional,
potentially quasi-long-range contributions to the entanglement entropy.
Motivated by the recently discovered incompressible insulating phase in the
bilayer graphene exciton experiment [arXiv:2306.16995], we study using
bosonization two Coulomb-coupled spinless quantum wires and examine the
possibility of realizing the similar phenomenology in one dimension. We explore
the possible phases as functions of $k_{F}$'s and interactions. We show that an
incompressible insulating phase can arise for two lightly doped electron-hole
quantum wires (i.e., $k_{F1}=-k_{F2}$ and small $|k_{F1}|$) due to strong
interwire interactions. Such an insulating phase forms a parity-even
wire-antisymmetric charge density wave without interwire phase coherence, which
melts to a phase allowing for a perfect negative drag upon heating. The
finite-temperature response is qualitatively consistent with the ``exciton
solid'' phenomenology in the bilayer graphene exciton experiment.
Starting from Halperin multilayer systems we develop a hierarchical scheme
that generates, bosonic and fermionic, single-layer quantum Hall states (or
vacua) of arbitrary filling factor. Our scheme allows for the insertion of
quasiparticle excitations with either Abelian or non-Abelian statistics and
quantum numbers that depend on the nature of the original vacuum. Most
importantly, it reveals a fusion mechanism for quasielectrons and
magnetoexcitons that generalizes ideas about particle fractionalization
introduced in A. Bochniak, Z. Nussinov, A. Seidel, and G. Ortiz, Commun. Phys.
5, 171 (2022) for the case of Laughlin fluids. In addition, in the second
quantization representation, we uncover the inherent topological quantum order
characterizing these vacua. In particular, we illustrate the methodology by
constructing generalized composite (generalized Read) operators for the
non-Abelian Pfaffian and Hafnian quantum fluid states.
The Benalcazar-Bernevig-Hughes (BBH) quadrupole insulator model is a
cornerstone model for higher-order topological phases. It requires \pi-flux
threading through each plaquette of the two-dimensional Su-Schrieffer-Heeger
model. Recent studies showed that particular \pi-flux patterns can modify the
fundamental domain of momentum space from the shape of a torus to a Klein
bottle with emerging topological phases. By designing different \pi-flux
patterns, we propose two types of Klein-bottle BBH models. These models show
rich topological phases, including Klein-bottle quadrupole insulators and Dirac
semimetals. The phase with nontrivial Klein-bottle topology shows twined edge
modes at open boundaries. These edge modes can further support second-order
topology, yielding a quadrupole insulator. Remarkably, both models are robust
against flux perturbations. Moreover, we show that different \pi-flux patterns
dramatically affect the phase diagram of the Klein-bottle BBH models. Going
beyond the original BBH model, Dirac semimetal phases emerge in Klein-bottle
BBH models featured by the coexistence of twined edge modes and bulk Dirac
points.
We propose a new avenue in which percolation, which has been much associated
with critical phase transitions, can also dictate the asymptotic dynamics of
non-Hermitian systems by breaking PT symmetry. Central to it is our
newly-designed mechanism of topologically guided gain, where chiral edge
wavepackets in a topological system experience non-Hermitian gain or loss based
on how they are topologically steered. For sufficiently wide topological
islands, this leads to irreversible growth due to positive feedback from
interlayer tunneling. As such, a percolation transition that merges small
topological islands into larger ones also drives the edge spectrum across a
real to complex transition. Our discovery showcases intriguing dynamical
consequences from the triple interplay of chiral topology, directed gain and
interlayer tunneling, and suggests new routes for the topology to be harnessed
in the control of feedback systems.
Advancements in semiconductor fabrication over the past decade have catalyzed
extensive research into all-optical devices driven by exciton-polariton
condensates. Preliminary validations of such devices, including transistors,
have shown encouraging results even under ambient conditions. A significant
challenge still remains for large scale application however: the lack of a
robust solver that can be used to simulate complex nonlinear systems which
require an extended period of time to stabilize. Addressing this need, we
propose the application of a machine-learning-based Fourier Neural Operator
approach to find the solution to the Gross-Pitaevskii equations coupled with
extra exciton rate equations. This work marks the first direct application of
Neural Operators to an exciton-polariton condensate system. Our findings show
that the proposed method can predict final-state solutions to a high degree of
accuracy almost 1000 times faster than CUDA-based GPU solvers. Moreover, this
paves the way for potential all-optical chip design workflows by integrating
experimental data.
We investigate the quasi-particle and transport properties of a model
describing interacting Dirac and Weyl semimetals in the presence of local
Hubbard repulsion $U$, where we explicitly include a deviation from the
linearity of the energy-momentum dispersion through an intermediate-energy
scale $\Lambda$. Our focus lies on the correlated phase of the semimetal. At
the nodal point, the renormalization of spectral weight at a fixed temperature
$T$ exhibits a weak dependence on $\Lambda$ but is sensitive to the proximity
to the Mott transition. Conversely, the scattering rate of quasi-particles and
the resistivity display high-temperature exponents that crucially rely on
$\Lambda$, leading to a crossover towards a conventional Fermi-liquid behaviour
at finite T. Finally, by employing the Nernst-Einstein relation for
conductivity, we identify a corresponding density crossover as a function of
the chemical potential.
Two-dimensional transition metal dichalcogenides host interesting physics and
have potential applications in various fields. Recently, it is shown
experimentally and theoretically that semiconducting monolayer PtSe$_2$
nanoflakes with neutral zigzag edges are stable. Here, we study PtSe$_2$
nanoribbons with the stable edges through first-principles investigation, and
find relativstic electron energy dispersion with large Rashba spin splitting in
the low-energy bands (even $N$) which originates from the nanoribbon edges. It
is shown that there exists SU(2) spin symmetry in both of the conduction and
valence bands, which implies conserved spin transport or persistent spin helix
(conserved spin structure) along each edge. When the inter-edge interaction
becomes week, a nearly-perfect Dirac fermion system can be achieved for each
nanoribbon edge through combining the valence and conduction bands. These
electronic systems can realize important effects and could be useful for
high-performance spintronic and optoelectronic applications.
We consider magnetic Weyl semimetals. First of all we review relation of
intrinsic anomalous Hall conductivity, band contribution to intrinsic magnetic
moment, and the conductivity of chiral separation effect (CSE) to the
topological invariants written in terms of the Wigner transformed Green
functions (with effects of interaction and disorder taken into account). Next,
we concentrate on the CSE. The corresponding bulk axial current would result in
accumulation of particles and holes of opposite chiralities at the surface of
the sample. However, this accumulation is compensated by the flow of the states
in momentum space along the Fermi arcs. Together with the bulk CSE current this
flow forms closed Weyl orbits. Their detection can be considered as
experimental discovery of chiral separation effect. Previously it was proposed
to detect Weyl orbits through the observation of quantum oscillations
\cite{Potter_2014} . We propose the alternative way to detect existence of Weyl
orbits through the observation of their contributions to Hall conductance.
Recent experimental observations of the fractional quantum anomalous Hall
effect in spin/valley polarized moir\'{e} systems call for a more expansive
theoretical exploration of strongly correlated physics in partially filled
topological bands. In this work we study a state that we refer to as the
conjugate-composite Fermi liquid (cCFL), which arises when a pair of Chern
bands with opposite Chern numbers are both half-filled. We demonstrate that the
cCFL is the parent state of various interesting phenomena. As an example, we
demonstrate that with the existence of an inplane spin order, the cCFL could be
driven into a quantum bad metal phase, in the sense that it is a metallic phase
whose zero temperature longitudinal resistivity is finite, but far greater than
the Mott-Ioffe-Regal limit, i.e. $\rho^e_{xx} \gg h/e^2$. The bad metal phase
is also accompanied with a new Wiedemann-Franz law, meaning the thermal
conductivity is proportional to the electrical resistivity rather than
conductivity. Other proximate phases of the cCFL such as superconductivity and
a chiral spin liquid phase can occur when the composite fermions (CF) form the
inter-valley CF-exciton condensate.
Fe$_{1.057(7)}$Te undergoes a first-order tetragonal to monoclinc structural
transition at T$_{S} \sim 70$ K, breaking the C$_{4}$ lattice symmetry and
simultaneously breaking time reversal symmetry with bicollinear magnetic order.
We investigate the soft acoustic lattice dynamics near this combined
magneto-structural transition. We apply spherically neutron polarimetry to
study the static magnetism near this transition, characterized with x-ray
powder diffraction, and find no evidence of static incommensurate magnetic
correlations near the onset of monoclinic and bicollinear antiferromagnetic
order. This fixes the position of our single crystal sample in the Fe$_{1+x}$Te
phase diagram in the magnetic bicollinear region and illustrates that our
sample statically undergoes a transition from a paramagnetic phase to a
low-temperature bicollinear phase. We then apply neutron spectroscopy to study
the acoustic phonons, related to elastic deformations of the lattice. We find a
temperature dependent soft acoustic branch for phonons propagating along [010]
and polarized along [100]. The slope of this acoustic phonon branch is
sensitive to the elastic constant $C_{66}$ and the shear modulus. The
temperature dependence of this branch displays a softening with a minimum near
the magneto-structural transition of T$_{S}$ $\sim$ 70 K and a recovery within
the magnetically ordered low temperature phase. Soft acoustic instabilities are
present in the collinear phases of the chalcogenides Fe$_{1+x}$Te where nematic
order found in Fe$_{1+\delta}$Se is absent. We speculate, based on localized
single-ion magnetism, that the relative energy scale of magnetic spin-orbital
coupling on the Fe$^{2+}$ transition metal ion is important for the presence of
a nematicity in the chalcogenides.
Fractional Chern insulators (FCI) were proposed theoretically about a decade
ago. These exotic states of matter are fractional quantum Hall states realized
when a nearly flat Chern band is partially filled, even in the absence of an
external magnetic field. Recently, exciting experimental signatures of such
states have been reported in twisted MoTe$_2$ bilayer systems. Motivated by
these experimental and theoretical progresses, in this paper, we develop a
projective construction for the composite fermion states (either the Jain's
sequence or the composite Fermi liquid) in a partially filled Chern band with
Chern number $C=\pm1$, which is capable of capturing the microscopics, e.g.,
symmetry fractionalization patterns and magnetoroton excitations. On the
mean-field level, the ground states' and excitated states' composite fermion
wavefunctions are found self-consistently in an enlarged Hilbert space. Beyond
the mean-field, these wavefunctions can be projected back to the physical
Hilbert space to construct the electronic wavefunctions, allowing direct
comparison with FCI states from exact diagonalization on finite lattices. We
find that the projected electronic wavefunction corresponds to the
\emph{combinatorial hyperdeterminant} of a tensor. When applied to the
traditional Galilean invariant Landau level context, the present construction
exactly reproduces Jain's composite fermion wavefunctions. We apply this
projective construction to the twisted bilayer MoTe$_2$ system. Experimentally
relevant properties are computed, such as the magnetoroton band structures and
quantum numbers.
We study the topological properties of the Haldane and modified Haldane
models in $\alpha$-$T_{3}$ lattice. The band structures and phase diagrams of
the system are investigated. Individually, each model undergoes a distinct
phase transition: (i) the Haldane-only model experiences a topological phase
transition from the Chern insulator ($\mathcal{C} = 1$) phase to the higher
Chern insulator ($\mathcal{C} = 2$) phase; while (ii) the modified-Haldane-only
model experiences a phase transition from the topological metal ($\mathcal{C} =
2$) phase to the higher Chern insulator ($\mathcal{C} = 2$) phase and we show
that $\mathcal{C}$ is insufficient to characterize this system because
$\mathcal{C}$ remains unchanged before and after the phase transition. By
plotting the Chern number and $\mathcal{C}$ phase diagram, we show that in the
presence of both Haldane and modified Haldane models in the $\alpha$-$T_{3}$
lattice, the interplay between the two models manifests three distinct
topological phases, namely the $\mathcal{C} = 1$ Chern insulator (CI) phase,
$\mathcal{C} = 2$ higher Chern insulator (HCI) phase and $\mathcal{C} = 2$
topological metal (TM) phase. These results are further supported by the
$\alpha$-$T_{3}$ zigzag edge states calculations. Our work elucidates the rich
phase evolution of Haldane and modified Haldane models as $\alpha$ varies
continuously from $0$ to $1$ in an $\alpha$-$T_3$ model.

Date of feed: Tue, 12 Dec 2023 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) **Topologically compatible non-Hermitian skin effect. (arXiv:2312.05315v1 [cond-mat.mes-hall])**

Rijia Lin, Linhu Li

**Collision times of multivariate Bessel processes with their Weyl chambers' boundaries and their Hausdorff dimension. (arXiv:2312.05420v1 [math.PR])**

Nicole Hufnagel, Sergio Andraus

**Quasi-phase-matched up- and down-conversion in periodically poled layered semiconductors. (arXiv:2312.05444v1 [physics.optics])**

Chiara Trovatello, Carino Ferrante, Birui Yang, Josip Bajo, Benjamin Braun, Xinyi Xu, Zhi Hao Peng, Philipp K. Jenke, Andrew Ye, Jiwoong Park, Philip Walther, Lee A. Rozema, Cory Dean, Andrea Marini, Giulio Cerullo, P. James Schuck

**Chiral symmetry breaking and topological charge of graphene nanoribbons. (arXiv:2312.05487v1 [cond-mat.mes-hall])**

Hyun Cheol Lee, S.-R. Eric Yang

**Broken weak and strong spin rotational symmetries and tunable interaction between phonon and the continuum in Cr2Ge2Te6. (arXiv:2312.05533v1 [cond-mat.str-el])**

Atul G. Chakkar, Deepu Kumar, Pradeep Kumar

**Chemical potential of magnetic skyrmion quasiparticles in heavy metal/iron bilayers. (arXiv:2312.05535v1 [cond-mat.mtrl-sci])**

Balázs Nagyfalusi, László Udvardi, László Szunyogh, Levente Rózsa

**Topological Interfaces of Luttinger Liquids. (arXiv:2312.05566v1 [cond-mat.str-el])**

Ananda Roy, Hubert Saleur

**Large nonlinear Hall effect and Berry curvature in KTaO3 based two-dimensional electron gas. (arXiv:2312.05578v1 [cond-mat.mtrl-sci])**

Jinfeng Zhai, Mattia Trama, Hao Liu, Zhifei Zhu, Yinyan Zhu, Carmine Antonio Perroni, Roberta Citro, Pan He, Jian Shen

**Infrared photodetection in graphene-based heterostructures: bolometric and thermoelectric effects at the tunneling barrier. (arXiv:2312.05612v1 [cond-mat.mes-hall])**

Dmitry A. Mylnikov, Mikhail A. Kashchenko, Kirill N. Kapralov, Davit A. Ghazaryan, Evgenii E. Vdovin, Sergey V. Morozov, Kostya S. Novoselov, Denis A. Bandurin, Alexander I. Chernov, Dmitry A. Svintsov

**Pressure induced Topological Dirac semimetals in XCdP(X=Na, K). (arXiv:2312.05636v1 [cond-mat.mtrl-sci])**

Shivendra Kumar Gupta, Nikhilesh Singh, Saurabh Kumar Sen, Poorva Singh

**Plasmonic skyrmion quantum thermodynamics. (arXiv:2312.05656v1 [quant-ph])**

Vipin Vijayan, L. Chotorlishvili, A. Ernst, M. I. Katsnelson, S. S. P. Parkin, S. K. Mishra

**Topological conditions for impurity effects in graphene nanosystems. (arXiv:2312.05812v1 [cond-mat.mes-hall])**

Y.G. Pogorelov, V.M. Loktev

**Third order nonlinear transport properties in topological chiral antiferromagnetic semimetal CoNb3S6. (arXiv:2312.05824v1 [cond-mat.mtrl-sci])**

Junjian Mi, Jialin Li, Miaocong Li, Sheng Xu, Shuang Yu, Zheng Li, Xinyi Fan, Huanfeng Zhu, Qian Tao, Linjun Li, Zhuan Xu

**Imaging the Ettingshausen effect and cryogenic thermoelectric cooling in a van der Waals semimetal. (arXiv:2312.05850v1 [cond-mat.mes-hall])**

T. Völkl, A. Aharon-Steinberg, T. Holder, E. Alpern, N. Banu, A. K. Pariari, Y. Myasoedov, M. E. Huber, M. Hücker, E. Zeldov

**Thermoelectric Properties of Armchair Graphene Nanoribbons with Array Characteristics. (arXiv:2312.05874v1 [cond-mat.mes-hall])**

David M T Kuo

**Universal patterns of skyrmion magnetizations unveiled by defect implantation. (arXiv:2312.05903v1 [cond-mat.mtrl-sci])**

Imara Lima Fernandes, Samir Lounis

**Van Hove singularity-induced negative magnetoresistance in Dirac semimetals. (arXiv:2312.05918v1 [cond-mat.mes-hall])**

Kai-He Ding, Zhen-Gang Zhu

**Large quantum nonreciprocity in plasmons dragged by drifting electrons. (arXiv:2312.05949v1 [cond-mat.mes-hall])**

Debasis Dutta, Amit Agarwal

**Optomechanical methodology for characterizing the thermal properties of 2D materials. (arXiv:2312.06070v1 [physics.app-ph])**

Hanqing Liu, Hatem Brahmi, Carla Boix-Constant, Herre S. J. van der Zant, Peter G. Steeneken, Gerard J. Verbiest

**DFT based investigation of structural, elastic, optoelectronic, thermophysical and superconducting state properties of binary Mo3P at different pressures. (arXiv:2312.06073v1 [cond-mat.mtrl-sci])**

Md. Sohel Rana, Razu Ahmed, Md. Sajidul Islam, R.S. Islam, S.H. Naqib

**Self-powered programmable van der Waals photodetectors with nonvolatile semi-floating gate. (arXiv:2312.06142v1 [cond-mat.mes-hall])**

Fan Liu, Xi Lin, Yuting Yan, Xuetao Gan, Yingchun Cheng, Xiaoguang Luo

**Approaching the robust linearity in dual-floating van der Waals photodiode. (arXiv:2312.06157v1 [cond-mat.mes-hall])**

Jinpeng Xu, Xiaoguang Luo, Xi Lin, Xi Zhang, Fan Liu, Yuting Yan, Siqi Hu, Mingwen Zhang, Nannan Han, Xuetao Gan, Yingchun Cheng, Wei Huang

**Universality of Anderson Localization Transitions in the Integer and Fractional Quantum Hall Regime. (arXiv:2312.06194v1 [cond-mat.mes-hall])**

Simrandeep Kaur, Tanima Chanda, Kazi Rafsanjani Amin, Kenji Watanabe, Takashi Taniguchi, Unmesh Ghorai, Yuval Gefen, G. J. Sreejith, Aveek Bid

**Giant ferroelectric polarization in ZrO2 thin film enhanced by an AFE-to-FE phase transition. (arXiv:2312.06216v1 [cond-mat.mtrl-sci])**

Xianglong Li, Zengxu Xu, Songbai Hu, Mingqiang Gu, Yuanmin Zhu, Qi Liu, Yihao Yang, Mao Ye, Lang Chen

**Electrically Tunable Fine Structure of Negatively Charged Excitons in Gated Bilayer Graphene Quantum Dots. (arXiv:2312.06264v1 [cond-mat.mes-hall])**

Katarzyna Sadecka, Yasser Saleem, Daniel Miravet, Matthew Albert, Marek Korkusinski, Gabriel Bester, Pawel Hawrylak

**Edge-State-Mediated RKKY Coupling in Graphene Nanoflakes. (arXiv:2312.06277v1 [cond-mat.mes-hall])**

Ahmet Utku Canbolat, Ozgur Cakir

**Towards a phase diagram of the topologically frustrated XY chain. (arXiv:2312.06291v1 [cond-mat.stat-mech])**

Daniel Sacco Shaikh, Alberto Giuseppe Catalano, Fabio Cavaliere, Fabio Franchini, Maura Sassetti, Niccolò Traverso Ziani

**Inelastic Light Scattering in the Vicinity of a Single-Atom Quantum Point Contact in a Plasmonic Picocavity. (arXiv:2312.06339v1 [cond-mat.mes-hall])**

Shuyi Liu, Franco P. Bonafe, Heiko Appel, Angel Rubio, Martin Wolf, Takashi Kumagai

**Many-body effects on the quasiparticle band structure and optical response of single-layer penta-NiN$_2$. (arXiv:2312.06394v1 [cond-mat.mtrl-sci])**

Enesio Marinho Jr., Cesar E. P. Villegas, Pedro Venezuela, Alexandre R. Rocha

**Nanoscale strain manipulation of smectic susceptibility in kagome superconductors. (arXiv:2312.06407v1 [cond-mat.supr-con])**

Yidi Wang, Hong Li, Siyu Cheng, He Zhao, Brenden R. Ortiz, Andrea Capa Salinas, Stephen D. Wilson, Ziqiang Wang, Ilija Zeljkovic

**Micromagnets dramatically enhance effects of viscous hydrodynamic flow in two-dimensional electron fluid. (arXiv:2205.08110v2 [cond-mat.mes-hall] UPDATED)**

Jack N. Engdahl, Aydin Cem Keser, Oleg P. Sushkov

**Curvature-induced superconductivity enhancement for ultra-thin superconducting films. (arXiv:2205.14373v3 [cond-mat.mes-hall] UPDATED)**

Long Du, Yong-Long Wang, Minsi Li, Jiahong Gu, Lijuan Zhou, Guangzhen Kang, Huiqing Tang, Qinghua Chen

**Topological $p_x+ip_y$ inter-valley coherent state in Moir\'e MoTe$_2$/WSe$_2$ heterobilayers. (arXiv:2206.11666v3 [cond-mat.mtrl-sci] UPDATED)**

Ying-Ming Xie, Cheng-Ping Zhang, K. T. Law

**Symmetry-Protected Topological Superconductivity in Magnetic Metals. (arXiv:2208.10225v2 [cond-mat.supr-con] UPDATED)**

Zhongyi Zhang, Zhenfei Wu, Chen Fang, Fu-chun Zhang, Jiangping Hu, Yuxuan Wang, Shengshan Qin

**Effects of topological and non-topological edge states on information propagation and scrambling in a Floquet spin chain. (arXiv:2210.15302v2 [cond-mat.stat-mech] UPDATED)**

Samudra Sur, Diptiman Sen

**Triclinic BiFeO3: A room-temperature multiferroic phase with enhanced magnetism and resistivity. (arXiv:2211.03123v3 [cond-mat.mtrl-sci] UPDATED)**

Md Sariful Sheikh, Tushar Kanti Bhowmik, Alo Dutta, Sujoy Saha, Chhatra R. Joshi, T. P. Sinha

**Phase-engineering the Andreev band structure of a three-terminal Josephson junction. (arXiv:2302.14535v2 [cond-mat.mes-hall] UPDATED)**

M. Coraiola, D. Z. Haxell, D. Sabonis, H. Weisbrich, A. E. Svetogorov, M. Hinderling, S. C. ten Kate, E. Cheah, F. Krizek, R. Schott, W. Wegscheider, J. C. Cuevas, W. Belzig, F. Nichele

**Evolution from quantum anomalous Hall insulator to heavy-fermion semimetal in magic-angle twisted bilayer graphene. (arXiv:2304.14064v3 [cond-mat.str-el] UPDATED)**

Cheng Huang, Xu Zhang, Gaopei Pan, Heqiu Li, Kai Sun, Xi Dai, Ziyang Meng

**Low-dimensional quantum gases in curved geometries. (arXiv:2305.05584v3 [cond-mat.quant-gas] UPDATED)**

A. Tononi, L. Salasnich

**Tuning electronic properties in transition metal dichalcogenides MX$_2$ (M= Mo/W, X= S/Se) heterobilayers with strain and twist angle. (arXiv:2305.09223v3 [cond-mat.mtrl-sci] UPDATED)**

Ravina Beniwal, M. Suman Kalyan, Nicolas Leconte, Jeil Jung, Bala Murali Krishna Mariserla, S. Appalakondaiah

**Effect of vacancies on magnetic correlations and conductance in graphene nanoflakes with realistic Coulomb interaction. (arXiv:2305.11085v2 [cond-mat.str-el] UPDATED)**

V. S. Protsenko, A. A. Katanin

**Magnetic exchange interactions at the proximity of a superconductor. (arXiv:2306.02906v2 [cond-mat.supr-con] UPDATED)**

Uriel Allan Aceves Rodríguez, Filipe Souza Mendes Guimarães, Sascha Brinker, Samir Lounis

**Lifshitz transitions and angular conductivity diagrams in metals with complex Fermi surfaces. (arXiv:2306.12225v3 [cond-mat.mtrl-sci] UPDATED)**

A. Ya. Maltsev

**Laughlin's quasielectron as a non-local composite fermion. (arXiv:2306.13972v2 [cond-mat.str-el] UPDATED)**

Alberto Nardin, Leonardo Mazza

**Nontrivial worldline winding in non-Hermitian quantum systems. (arXiv:2307.01260v2 [quant-ph] UPDATED)**

Shi-Xin Hu, Yongxu Fu, Yi Zhang

**Correlated insulator in two Coulomb-coupled quantum wires. (arXiv:2307.13688v2 [cond-mat.str-el] UPDATED)**

Yang-Zhi Chou, Sankar Das Sarma

**Fusion mechanism for quasiparticles and topological quantum order in the lowest Landau level. (arXiv:2308.03548v2 [cond-mat.str-el] UPDATED)**

Arkadiusz Bochniak, Gerardo Ortiz

**Klein-bottle quadrupole insulators and Dirac semimetals. (arXiv:2309.07784v4 [cond-mat.mes-hall] UPDATED)**

Chang-An Li, Junsong Sun, Song-Bo Zhang, Huaiming Guo, Björn Trauzettel

**Percolation-induced PT symmetry breaking. (arXiv:2309.15008v2 [cond-mat.stat-mech] UPDATED)**

Mengjie Yang, Ching Hua Lee

**Exciton-Polariton Condensates: A Fourier Neural Operator Approach. (arXiv:2309.15593v2 [cond-mat.quant-gas] UPDATED)**

Surya T. Sathujoda, Yuan Wang, Kanishk Gandhi

**Interacting nodal semimetals with non-linear bands. (arXiv:2310.03653v2 [cond-mat.str-el] UPDATED)**

Arianna Poli, Niklas Wagner, Max Fischer, Alessandro Toschi, Giorgio Sangiovanni, Sergio Ciuchi

**Large Rashba spin splitting, double SU(2) spin symmetry, and pure Dirac fermion system in PtSe$_2$ nanoribbon. (arXiv:2311.09931v2 [cond-mat.mes-hall] UPDATED)**

Bo-Wen Yu, Bang-Gui Liu

**Weyl orbits as probe of chiral separation effect in magnetic Weyl semimetals. (arXiv:2311.12712v3 [cond-mat.mes-hall] UPDATED)**

M.A.Zubkov

**The Conjugate Composite Fermi Liquid. (arXiv:2311.16250v2 [cond-mat.str-el] UPDATED)**

Nayan Myerson-Jain, Chao-Ming Jian, Cenke Xu

**Acoustic lattice instabilities at the magneto-structural transition in Fe$_{1.057(7)}$Te. (arXiv:2311.16853v2 [cond-mat.str-el] UPDATED)**

K. Guratinder, E. Chan, E. E. Rodriguez, J. A. Rodriguez-Rivera, U. Stuhr, A. Stunault, R. Travers, M. A. Green, N. Qureshi, C. Stock

**Hyperdeterminants and Composite fermion States in Fractional Chern Insulators. (arXiv:2312.00636v2 [cond-mat.str-el] UPDATED)**

Xiaodong Hu, Di Xiao, Ying Ran

**Interplay between Haldane and modified Haldane models in $\alpha$-$T_{3}$ lattice: Band structures, phase diagrams and edge states. (arXiv:2312.00642v2 [cond-mat.str-el] UPDATED)**

Kok Wai Lee, Pei-Hao Fu, Yee Sin Ang

Found 12 papers in prb Monolayer ${\mathrm{FeTe}}_{1−x}{\mathrm{Se}}_{x}$ films grown on a ${\mathrm{SrTiO}}_{3}(001)$ substrate is a promising platform to explore both high-temperature and topological superconductivity. Using molecular beam epitaxy, we successfully synthesized monolayer ${\mathrm{FeTe}}_{1−x}{\mathrm{Se}… Topological defects are of fundamental interest to wide branches of physics. Exploiting the structural evolutions and behaviors of topological defects across the phase transition is vital in understanding complicated condensed matter. Via presetting different initial azimuthal orientations of a squa… Skyrmions are localized swirling noncoplanar spin textures offering a promising revolution in future spintronic applications. These topologically nontrivial spin textures lead to an additional contribution to the Hall effect, called the topological Hall effect. Here, we investigate the origin of the… By performing first-principles calculations in conjunction with Monte Carlo simulations, we systematically investigated the frustrated magnetic states induced by in-plane compressive strain in ${\mathrm{LiCrTe}}_{2}$. Our calculations support the idea that the magnetic ground state of the ${\mathrm{… Motivated by the recently discovered incompressible insulating phase in the bilayer graphene exciton experiment [Zeng The phonon thermal transport properties of twisted bilayer graphene are investigated using lattice dynamics and the Boltzmann transport equation. The thermal conductivities of $13.{2}^{∘}$ and $21.{8}^{∘}$ twisted configurations are 56 and 36% lower than the untwisted configuration, which has a room… Zintl-phase compounds garner attention as promising thermoelectric materials due to observations of phonon-glass electron-crystal (PGEC) behavior, in combination with tunability that allows optimization of properties and doping. However, this is very much dependent on the specific materials, and und… We investigate transport properties of stable gate-defined quantum dots formed in an ${\mathrm{InSb}}_{0.87}{\mathrm{As}}_{0.13}$ quantum well. High $g$ factor and strong spin-orbit coupling make ${\mathrm{InSb}}_{x}{\mathrm{As}}_{1−x}$ a promising platform for exploration of topological superconduc…

Date of feed: Tue, 12 Dec 2023 04:17:04 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) **Spatial inhomogeneity of superconducting gap in epitaxial monolayer ${\mathrm{FeTe}}_{1−x}{\mathrm{Se}}_{x}$ films**

Yaowu Liu, Luxin Li, Zheng Xie, Zichun Zhang, Sidan Chen, Lichen Ji, Wei Chen, Xinyu Zhou, Xiaopeng Hu, Xi Chen, Qi-Kun Xue, and Shuai-Hua Ji

Author(s): Yaowu Liu, Luxin Li, Zheng Xie, Zichun Zhang, Sidan Chen, Lichen Ji, Wei Chen, Xinyu Zhou, Xiaopeng Hu, Xi Chen, Qi-Kun Xue, and Shuai-Hua Ji

[Phys. Rev. B 108, 214514] Published Mon Dec 11, 2023

**Azimuthal orientation guided topological defect evolution across the nematic-smectic phase transition**

Jin-Bing Wu, Sai-Bo Wu, and Wei Hu

Author(s): Jin-Bing Wu, Sai-Bo Wu, and Wei Hu

[Phys. Rev. B 108, 224107] Published Mon Dec 11, 2023

**Revealing the origin of the topological Hall effect in the centrosymmetric shape memory Heusler alloy ${\mathrm{Mn}}_{2}\mathrm{NiGa}$: A combined experimental and theoretical investigation**

Shivani Rastogi, Nisha Shahi, Vishal Kumar, Gaurav K. Shukla, Satadeep Bhattacharjee, and Sanjay Singh

Author(s): Shivani Rastogi, Nisha Shahi, Vishal Kumar, Gaurav K. Shukla, Satadeep Bhattacharjee, and Sanjay Singh

[Phys. Rev. B 108, 224108] Published Mon Dec 11, 2023

**Strain-induced frustrated helimagnetism and topological spin textures in ${\mathrm{LiCrTe}}_{2}$**

Weiyi Pan, Xueyang Li, and Junsheng Feng

Author(s): Weiyi Pan, Xueyang Li, and Junsheng Feng

[Phys. Rev. B 108, 224417] Published Mon Dec 11, 2023

**Correlated insulator in two Coulomb-coupled quantum wires**

Yang-Zhi Chou and Sankar Das Sarma

Author(s): Yang-Zhi Chou and Sankar Das Sarma*et al.*, arXiv:2306.16995], we study using bosonization two Coulomb-coupled spinless quantum wires and examine the possibility of realizing the similar phenomenology in one dimension…

[Phys. Rev. B 108, 235135] Published Mon Dec 11, 2023

**Understanding phonon thermal transport in twisted bilayer graphene**

Shahid Ahmed, Shadab Alam, and Ankit Jain

Author(s): Shahid Ahmed, Shadab Alam, and Ankit Jain

[Phys. Rev. B 108, 235202] Published Mon Dec 11, 2023

**Rattling vibrations and occupied antibonding states yield intrinsically low thermal conductivity of the Zintl-phase compound KSrBi**

Congying Wei, Zhenzhen Feng, Yuli Yan, Gaofeng Zhao, Yuhao Fu, and David J. Singh

Author(s): Congying Wei, Zhenzhen Feng, Yuli Yan, Gaofeng Zhao, Yuhao Fu, and David J. Singh

[Phys. Rev. B 108, 235203] Published Mon Dec 11, 2023

**Electronic $g$ factor and tunable spin-orbit coupling in a gate-defined InSbAs quantum dot**

S. Metti, C. Thomas, and M. J. Manfra

Author(s): S. Metti, C. Thomas, and M. J. Manfra

[Phys. Rev. B 108, 235306] Published Mon Dec 11, 2023

**Erratum: Maximizing intrinsic anomalous Hall effect by controlling the Fermi level in simple Weyl semimetal films [Phys. Rev. B 105, 201101 (2022)]**

Mizuki Ohno, Susumu Minami, Yusuke Nakazawa, Shin Sato, Markus Kriener, Ryotaro Arita, Masashi Kawasaki, and Masaki Uchida

Author(s): Mizuki Ohno, Susumu Minami, Yusuke Nakazawa, Shin Sato, Markus Kriener, Ryotaro Arita, Masashi Kawasaki, and Masaki Uchida

[Phys. Rev. B 108, 239902] Published Mon Dec 11, 2023

Transition out of a topological phase is typically characterized by discontinuous changes in topological invariants along with bulk gap closings. However, as a clean system is geometrically punctured, it is natural to ask the fate of an underlying topological phase. To understand this physics we int… [Phys. Rev. B 108, L220201] Published Mon Dec 11, 2023 |

Topological magnets host two sets of gauge fields: that of native Maxwell electromagnetism, owing to the magnetic dipole moment of its constituent microscopic moments, and that of the emergent gauge theory describing the topological phase. Here, we show that in quantum spin ice, the emergent magneti… [Phys. Rev. B 108, L220402] Published Mon Dec 11, 2023 |

Motivated by recent experiments observing the nonlinear planar Hall effect (NPHE) in nonmagnetic topological materials, we employ the density matrix method to consider all the intraband and interband transitions. This gives a deeper insight for the different mechanisms of NPHE on the same footing be… [Phys. Rev. B 108, L241104] Published Mon Dec 11, 2023 |

Found 2 papers in pr_res We devise a generic and experimentally accessible recipe to prepare boundary states of topological or nontopological quantum systems through an interplay between coherent Hamiltonian dynamics and local dissipation. Intuitively, our recipe harnesses the spatial structure of boundary states which vani… RhPb was initially recognized as one of CoSn-like compounds with $P6/mmm$ symmetry, containing an ideal kagome lattice of $d$-block atoms. However, theoretical calculations predict the realization of the phonon soft mode, which leads to the kagome lattice distortion and stabilization of the structur…

Date of feed: Tue, 12 Dec 2023 04:17:04 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) **Dissipative boundary state preparation**

Fan Yang, Paolo Molignini, and Emil J. Bergholtz

Author(s): Fan Yang, Paolo Molignini, and Emil J. Bergholtz

[Phys. Rev. Research 5, 043229] Published Mon Dec 11, 2023

**Phononic drumhead surface state in the distorted kagome compound RhPb**

Andrzej Ptok, William R. Meier, Aksel Kobiałka, Surajit Basak, Małgorzata Sternik, Jan Łażewski, Paweł T. Jochym, Michael A. McGuire, Brian C. Sales, Hu Miao, Przemysław Piekarz, and Andrzej M. Oleś

Author(s): Andrzej Ptok, William R. Meier, Aksel Kobiałka, Surajit Basak, Małgorzata Sternik, Jan Łażewski, Paweł T. Jochym, Michael A. McGuire, Brian C. Sales, Hu Miao, Przemysław Piekarz, and Andrzej M. Oleś

[Phys. Rev. Research 5, 043231] Published Mon Dec 11, 2023

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

< author missing >

**Manipulation of fractionalized charge in the metastable topologically entangled state of a doped Wigner crystal**

< author missing >

Found 2 papers in comm-phys Communications Physics, Published online: 09 December 2023; doi:10.1038/s42005-023-01465-w Communications Physics, Published online: 06 December 2023; doi:10.1038/s42005-023-01474-9**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) **Effects of aberrations on 3D optical topologies**

Ebrahim Karimi

**Three-dimensional non-Abelian Bloch oscillations and higher-order topological states**

Xiangdong Zhang