Found 50 papers in cond-mat The destruction of the Kondo effect in a local-moment metal can lead to a
topological non-Fermi-liquid phase, dubbed fractionalized Fermi liquid, with
spinon-type excitations and an emergent gauge field. We demonstrate that, if
the latter displays an internal $\pi$-flux structure, a chiral heavy-fermion
metal naturally emerges near the Kondo-breakdown transition. Utilizing a parton
mean-field theory describing the transition between a conventional heavy Fermi
liquid and a U(1) fractionalized Fermi liquid, we find a novel intermediate
phase near the transition whose emergent flux pattern spontaneously breaks both
translation and time-reversal symmetries. This phase is an orbital
antiferromagnet, and we discuss its relevance to pertinent experiments.
We study general maps from the space of rational CFTs with a fixed chiral
algebra and associated Chern-Simons (CS) theories to the space of qudit
stabilizer codes with a fixed generalized Pauli group. We consider certain
natural constraints on such a map and show that the map can be described as a
graph homomorphism from an orbifold graph, which captures the orbifold
structure of CFTs, to a code graph, which captures the structure of self-dual
stabilizer codes. By studying explicit examples, we show that this graph
homomorphism cannot always be a graph embedding. However, we construct a
physically motivated map from universal orbifold subgraphs of CFTs to operators
in a generalized Pauli group. We show that this map results in a self-dual
stabilizer code if and only if the surface operators in the bulk CS theories
corresponding to the CFTs in question are self-dual. For CFTs admitting a
stabilizer code description, we show that the full abelianized generalized
Pauli group can be obtained from twisted sectors of certain 0-form symmetries
of the CFT. Finally, we connect our construction with SymTFTs, and we argue
that many equivalences between codes that arise in our setup correspond to
equivalence classes of bulk topological surfaces under fusion with invertible
surfaces.
Single-component fractional quantum Hall states (FQHSs) at even-denominator
filling factors may host non-Abelian quasiparticles that are considered to be
building blocks of topological quantum computers. Such states, however, are
rarely observed in the lowest-energy Landau level, namely at filling factors
$\nu<1$. Here we report evidence for an even-denominator FQHS at $\nu=1/4$ in
ultra-high-quality two-dimensional hole systems confined to modulation-doped
GaAs quantum wells. We observe a deep minimum in the longitudinal resistance at
$\nu=1/4$, superimposed on a highly insulating background, suggesting a close
competition between the $\nu=1/4$ FQHS and the magnetic-field-induced, pinned
Wigner solid states. Our experimental observations are consistent with the very
recent theoretical calculations which predict that substantial Landau level
mixing, caused by the large hole effective mass, can induce composite fermion
pairing and lead to a non-Abelian FQHS at $\nu=1/4$. Our results demonstrate
that Landau level mixing can provide a very potent means for tuning the
interaction between composite fermions and creating new non-Abelian FQHSs.
The modification of magnetic properties in spatially inhomogeneous epitaxial
films of magnetic shape memory alloys in martensitic state with the temperature
variation has been studied. The proposed theoretical model is based on Landau
theory of martensitic transformation and statistical model of martensitic
state. It was shown that that spatial inhomogeneity of the material leads to
the dispersion of local martensitic transformation temperatures resulting in
the variation of local magnetic anisotropy values. This model allows describing
the dramatic ferromagnetic resonance line broadening observed in the
experiments in epitaxial films of magnetic shape memory alloys at low
temperatures.
Inner edge state with spin and valley degrees of freedom is a promising
candidate to design a dissipationless device due to the topological protection.
The central challenge for the application of inner edge state is to generate
and modulate the polarized currents. In this work, we discover a new mechanism
to generate fully valley- and spin-valley-polarized current caused by the Bloch
wavevector mismatch (BWM). Based on this mechanism, we design some serial-typed
inner-edge filters. With once of the BWM, the coincident states could be
divided into transmitted and reflected modes, which can serve as a valley or
spin-valley filter. In particular, while with twice of the BWM, the incident
current is absolutely reflected to support an off state with a specified valley
and spin, which is different from the gap effect. These findings give rise to a
new platform for designing valleytronics and spin-valleytronics.
The emergence of the first bilayer B48, which has been both theoretically
predicted and experimentally observed, as well as the recent experimental
synthesis of bilayer borophene on Ag and Cu, has generated tremendous curiosity
in the bilayer structure of boron clusters. However, the connection between the
bilayer cluster and the bilayer borophene remains unknown. By combining a
genetic algorithm and density functional theory calculations, a global search
for the low-energy structures of B63 clusters was conducted, revealing that the
Cs bilayer structure with three interlayer B-B bonds was the most stable
bilayer structure. This structure was further examined in terms of its
structural stability, chemical bonding, and aromaticity. Interestingly, the
interlayer bonds exhibited electronegativity and robust aromaticity.
Furthermore, the double aromaticity stemmed from diatropic currents originating
from virtual translational transitions at both the sigma and pi electrons. This
new boron bilayer is anticipated to enrich the concept of double aromaticity
and serve as a valuable precursor for bilayer borophene.
We investigate the topological characteristics of a recently discovered class
of semimetals in two dimensions on the honeycomb lattice. These semimetals
reside at the transition between two distinct topological insulators, each
existing in a nontrivial topological phase. As a result, these semimetals
exhibit specific topological properties, including the presence of edge modes.
In a preceding work, we demonstrated the topological robustness of this
semimetal phase against disorder and interactions. In this work, we delve
deeper into the semimetal's electronic properties, providing a precise
calculation of its Hall conductivity and response to circularly polarized
light, elaborating further on its bulk-edge correspondance leading to a half
topological semimetal.
This paper investigates the mathematical properties of independent-electron
models for twisted bilayer graphene by examining the density-of-states of
corresponding single-particle Hamiltonians using tools from semiclassical
analysis. This study focuses on a specific atomic-scale Hamiltonian
$H_{d,\theta}$ constructed from Density-Functional Theory, and a family of
moir\'e-scale Hamiltonians $H_{d,K,\theta}^{\rm eff}$ containing the
Bistritzer-MacDonald model. The parameter $d$ represents the interlayer
distance, and $\theta$ the twist angle. It is shown that the density-of-states
of $H_{d,\theta}$ and $H_{d,K,\theta}^{\rm eff}$ admit asymptotic expansions in
the twist angle parameter $\epsilon:=\sin(\theta/2)$. The proof relies on a
twisted version of the Weyl calculus and a trace formula for an exotic class of
pseudodifferential operators suitable for the study of twisted 2D materials. We
also show that the density-of-states of $H_{d,\theta}$ admits an asymptotic
expansion in $\eta:=\tan(\theta/2)$ and comment on the differences between the
expansions in $\epsilon$ and $\eta$.
A two-dimensional quantum spin Hall insulator exhibits one-dimensional
gapless spin-filtered edge channels allowing for dissipationless transport of
charge and spin. However, the sophisticated fabrication requirement of
two-dimensional materials and the low capacity of one-dimensional channels
hinder the broadening applications. We introduce a method to manipulate a
three-dimensional topological material to host a large number of
one-dimensional topological edge channels utilizing surface anisotropy. Taking
ZrTe5 as a model system, we realize a highly anisotropic surface due to the
synergistic effect of the lattice geometry and Coulomb interaction, and achieve
massive one-dimensional topological edge channels -- confirmed by electronic
characterization using angle-resolved photoemission spectroscopy, in
combination with first-principles calculations. Our work provides a new avenue
to engineer the topological properties of three-dimensional materials through
nanoscale tunning of surface morphology and opens up a promising prospect for
the development of low-power-consumption electronic nano devices based on
one-dimensional topological edge channels.
We present a hybrid numerical approach to simulate quantum many body problems
on two spatial dimensional quantum lattice models via the non-Abelian ab initio
version of the density matrix renormalization group method on state-of-the-art
high performance computing infrastructures. We demonstrate for the two
dimensional spinless fermion model and for the Hubbard model on torus geometry
that altogether several orders of magnitude in computational time can be saved
by performing calculations on an optimized basis and by utilizing hybrid
CPU-multiGPU parallelization. At least an order of magnitude reduction in
computational complexity results from mode optimization, while a further order
of reduction in wall time is achieved by massive parallelization. Our results
are measured directly in FLOP and seconds. A detailed scaling analysis of the
obtained performance as a function of matrix ranks and as a function of system
size up to $12\times 12$ lattice topology is discussed.
A two-dimensional hydrogen atom offers a promising alternative for describing
the quantum interaction between an electron and a proton in the presence of a
straight cosmic string. Reducing the hydrogen atom to two dimensions enhances
its suited to capture the cylindrical/conical symmetry associated with the
cosmic string, providing a more appropriate description of the physical system.
After solving Schr\"dinger's equation, we calculate the eigenenergies,
probability distribution function, and expected values for the hydrogen atom
with logarithmic potential under the influence of the topological defect. The
calculations for the 2D hydrogen atom are performed for the first time using
the Finite Difference Method. The results are presented through graphics,
tables, and diagrams to elucidate the system's physical properties. We have
verified that our calculations agree with a linear variational method result.
Our model leads to an interesting analogy with excitons in a two-dimensional
monolayer semiconductor located within a specific semiconductor region. To
elucidate this analogy, we present and discuss some interaction potentials and
their exciton eigenstates by comparing them with the results from the
literature.
Recently, there is an interest in studying the bulk-edge correspondence for
nonlinear eigenvalues problems in a two-dimensional topological system with
spin-orbit coupling. By introducing auxiliary eigenvalues, the nonlinear
bulk-edge correspondence was established. In this paper, taking the Haldane
model as an example, we address that such a correspondence will appear in two
dimensional topological system without spin-orbit coupling. The resulting edge
states are characterized by the Chern number of the auxiliary energy band. A
full phase diagram containing topological nontrivial phase, topological trivial
phase, and metallic phase is obtained. Our work generalizes the study of the
bulk-edge correspondence for nonlinear eigenvalue problems in two-dimensional
system.
Choosing the right spin polarization of electron enables its local injection
into the helical edge state with a well-defined momentum direction, despite the
uncertainty principle, owing to spin-momentum locking. This fact facilitates a
direct identification of odd-frequency pairing through parity measurement
(under frequency reversal) of the anomalous Green's function in a setup
comprising multi-terminal Josephson junction on the helical edge state of a 2D
topological insulator.
The experimental discoveries of fractional quantum anomalous Hall effects in
both transition metal dichalcogenide and pentalayer graphene moir\'e
superlattices have aroused significant research interest. In this work, we
theoretically study the fractional quantum anomalous Hall states (also known as
fractional Chern insulator states) in pentalayer graphene moir\'e superlattice.
Starting from the highest energy scale ($\sim\!1\,$eV) of the continuum model,
we first construct a renormalized low-energy model that applies to a lower
cutoff $\sim\!0.15\,$eV using renormalization group approach. Then, we study
the ground states of the renormalized low-energy model at filling 1 under
Hartree-Fock approximation in the presence of tunable but self-consistently
screend displacement field $D$ with several experimentally relevant background
dielectric constant $\epsilon_r$. Two competing Hartree-Fock states are
obtained at filling 1, which give rise to two types of topologically distrinct
isolated flat bands with Chern number 1 and 0, respectively. We continue to
explore the interacting ground states of the two types of isolated flat bands
at hole dopings of 1/3, 2/5, 3/5, and 2/3 (corresponding electron fillings of
2/3, 3/5, 2/5, 1/3 with respect to charge neutrality). Our exact-diagonlization
calculations suggest that the system stays in fractional Chern insulator (FCI)
state at 2/3 electron filling when $0.9\,\textrm{V/nm}\leq\!D\!\leq
0.92\,\textrm{V/nm}$ and $5\lessapprox\epsilon_r\lessapprox 6$; while no robust
FCI state is obtained at 1/3 electron filling in the experimentally relevant
parameter regime. We have also obtained composite-fermion type FCI ground
states at 3/5 electron filling within $0.9\,\textrm{V/nm}\leq\! D
\!\leq\!0.96\,\textrm{V/nm}$ and $\epsilon_r\approx 5$. These numerical results
are quantitatively consistent with experimental observations.
We investigate the domain wall network in twisted bilayer graphene (TBG)
under the influence of interlayer bias and screening effect from the layered
structure. Starting from the continuum model, we analyze the low-energy domain
wall modes within the moir\'e bilayer structure and obtain an analytical form
representing charge density distributions of the two-dimensional structure.
With the efficient calculation of screened electron-electron interaction
strengths both within and between the domain walls, we develop a bosonized
model that describes the correlated domain wall network. We demonstrate that
these interaction strengths can be modified through an applied interlayer bias,
screening length and dielectric materials, and show how the model can be
employed to investigate various properties of the domain wall network and its
stability. This finding reveals the TBG network as a promising platform for the
experimental manipulation of electron-electron interactions in low dimensions
and the study of strongly correlated matter. We point out that the
investigation not only enhances the understanding of domain wall modes in TBG
but also has broader implications for the development of graphene-based
devices.
Geometric frustration in systems with long-range interactions is a largely
unexplored phenomenon. In this work we analyse the ground state emerging from
the competition between a periodic potential and a Wigner crystal in one
dimension, consisting of a selforganized chain of particles with the same
charge. This system is a paradigmatic realization of the Frenkel-Kontorova
model with Coulomb interactions. We derive the action of a Coulomb soliton in
the continuum limit and demonstrate the mapping to a massive (1+1) Thirring
model with long-range interactions. Here, the solitons are charged fermionic
excitations over an effective Dirac sea. The mismatch between the periodicities
of potential and chain, giving rise to frustration, is a chemical potential
whose amplitude is majorly determined by the Coulomb self-energy. The
mean-field limit is a long-range antiferromagnetic spin chain with uniform
magnetic field and predicts that the commensurate, periodic structures form a
complete devil's staircase as a function of the charge density. Each step of
the staircase correspond to the interval of stability of a stable commensurate
phase and scales with the number $N$ of charges as $1/\ln N$. This implies that
there is no commensurate-incommensurate phase transition in the thermodynamic
limit. For finite systems, however, the ground state has a fractal structure
that could be measured in experiments with laser-cooled ions in traps.
We show that, contrary to common belief, the depolarizing electric field
generated by bound charges at thin-film surfaces can have a substantial impact
on the domain structure of an improper ferroelectric with topological defects.
In hexagonal-manganite thin films, we observe in phase-field simulations that
through the action of the depolarizing field, (i) the average magnitude of the
polarization density decreases, (ii) the local magnitude of the polarization
density decreases with increasing distance from the domain walls, and (iii)
there is a significant alteration of the domain-size distribution, which is
visualized with the pair-correlation function. We conclude that, in general, it
is not appropriate to ignore the effects of the depolarizing field for thin
film ferroelectrics.
The relationship between acoustic parameters and the microstructure of a
Cu30Zn brass plate subjected to plastic deformation was evaluated. The plate,
previously annealed at 550 {\deg}C for 30 minutes, was cold rolled to
reductions in the 10-70\% range. Using the pulse-echo method, linear ultrasonic
measurements were performed on each of the nine specimens, corresponding to the
nine different reductions, recording the wave times of flight of longitudinal
wave along the thickness axis. Subsequently, acoustic measurements were
performed to determine the nonlinear parameter ($\beta$) through the second
harmonic generation. X-ray diffraction analysis revealed a steady increase and
subsequent saturation of deformation twins at 40\% thickness reduction. At
higher deformations, the microstructure revealed the generation and
proliferation of shear bands, which coincided with a decrease in the twinning
structure and an increase in dislocation density rate. Longitudinal wave
velocity exhibited a 0.9\% decrease at 20\% deformation, followed by a
continuous increase of 2\% beyond this point. These results can be rationalized
as a competition between a proliferation of dislocations, which tends to
decrease the linear sound velocity, and a decrease in average grain size, which
tends to increase it. These variations are in agreement with the values
obtained with XRD, Vickers hardness and metallography measurements. The
nonlinear parameter $\beta$ shows a significant maximum, at the factor of 8
level, at 40\% deformation. This maximum correlates well with a similar
maximum, at a factor of ten level and also at 40\% deformation, of the twinning
fault probability.
This article reviews arguments that glass-forming liquids are different from
those of standard liquid-state theory. The latter typically have a viscosity in
the mPa$\cdot$s range and relaxation times of order picoseconds, while 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.
Tuning superconductivity in topological materials by means of chemical
substitution, electrostatic gating, or pressure is thought to be an effective
route towards realizing topological superconductivity with their inherent
Majorana fermions, the manipulation of which may form the basis for future
topological quantum computing. It has recently been established that the
pseudo-binary chalcogenides (ACh)m(Pn2Ch3)n (A = Ge, Mn, Pb, etc.; Pn = Sb or
Bi; Ch = Te, Se) may host novel topological quantum states such as the quantum
anomalous Hall effect and topological axion states. Here we map out the phase
diagram of one member in this series, the topological insulator candidate
GeSb4Te7 up to pressures of ~35 GPa, through a combination of electrical
resistance measurements, Raman spectroscopy, as well as first-principles
calculations. Three distinct superconducting phases emerge under the pressure
above ~11, ~17, and ~31 GPa, which are accompanied by concomitant structural
transitions, evidenced from the changes in the Raman modes. The
first-principles calculations validate the existence of a topological
insulating state at ambient pressure and predict two possible structural
transitions at 10 and 17 GPa, in agreement with the experimental observations.
Overall, our results establish the GeSb4Te7 family of materials as a fertile
arena for further exploring various topological phenomena, including
topological phase transitions and putative topological superconductivity.
Back-action refers to a response that retro-acts on a system to tailor its
properties with respect to an external stimulus. This self-induced effect
generally belongs to both the natural and technological realm, ranging from
neural networks to optics and electronic circuitry. In electronics, back-action
mechanisms are at the heart of many classes of devices such as amplifiers,
oscillators, and sensors. Here, we demonstrate that back-action can be
successfully exploited to achieve $\textit{non-reciprocal}$ transport in
superconducting circuits. Our device realizes a supercurrent diode, since the
dissipationless current flows in one direction whereas dissipative transport
occurs in the opposite direction. Supercurrent diodes presented so far rely on
magnetic elements or vortices to mediate charge transport or external magnetic
fields to break time-reversal symmetry. In our implementation, back-action
solely turns a conventional reciprocal superconducting weak link with no
asymmetry between the current bias directions into a diode, where the critical
current amplitude depends on the bias sign. The self-interaction of the
supercurrent with the device stems from the gate tunability of the critical
current, which uniquely promotes up to $\sim$88% of magnetic field-free signal
rectification and diode functionality with selectable polarity. The concept we
introduce is very general and can be applied directly to a large variety of
devices, thereby opening novel functionalities in superconducting electronics.
An optimal local quantum thermometer is a quantum many-body system that
saturates the fundamental lower bound for the thermal state temperature
estimation accuracy [L. Correa, et. al., Phys. Rev. Lett. 114, 220405 (2015)].
Such a thermometer has a particular energy level structure with a single ground
state and highly degenerated excited states manifold, with an energy gap
proportional to the estimated temperature. In this work, we show that the
optimal local quantum thermometer can be realized in an experimentally feasible
system of spinless fermions confined in a one-dimensional optical lattice
described by the Rice-Mele model. We characterize the system's sensitivity to
temperature changes in terms of quantum Fisher information and the classical
Fisher information obtained from experimentally available site occupation
measurements.
Recent experiments on ultracold dipoles in optical lattices open exciting
possibilities for the quantum simulation of extended Hubbard models. When
considered in one dimension, these models present at unit filling a
particularly interesting ground-state physics, including a symmetry-protected
topological phase known as Haldane insulator. We show that the tail of the
dipolar interaction beyond nearest-neighbors, which may be tailored by means of
the transversal confinement, does not only modify quantitatively the Haldane
insulator regime and lead to density waves of larger periods, but results as
well in unexpected insulating phases. These insulating phases may be
topological or topologically trivial, and are characterized by peculiar
correlations of the site occupations. These phases may be realized and observed
in state-of-the-art experiments.
The identification, description, and classification of topological features
is an engine of discovery and innovation in several fields of physics. This
research encompasses a broad variety of systems, from the integer and
fractional Chern insulators in condensed matter, to protected states in complex
photonic lattices in optics, and the structure of the QCD vacuum. Here, we
introduce another playground for topology: the dissipative dynamics of the
Sachdev-Ye-Kitaev (SYK) model, $N$ fermions in zero dimensions with strong
$q$-body interactions coupled to a Markovian bath. For $q = 4, 8, \ldots$ and
certain choices of $N$ and bath details, involving pseudo-Hermiticity, we find
a rectangular block representation of the vectorized Liouvillian that is
directly related to the existence of an anomalous trace of the unitary operator
implementing fermionic exchange. As a consequence of this rectangularization,
the Liouvillian has purely real modes for any coupling to the bath. Some of
them are demonstrated to be topological by an explicit calculation of the
spectral flow, leading to a symmetry-dependent topological index $\nu$.
Topological properties have universal features: they are robust to changes in
the Liouvillian provided that the symmetries are respected and they are also
observed if the SYK model is replaced by a quantum chaotic dephasing spin chain
in the same symmetry class. Moreover, the topological symmetry class can be
robustly characterized by the level statistics of the corresponding random
matrix ensemble. In the limit of weak coupling to the bath, topological modes
govern the approach to equilibrium, which may enable a direct path for
experimental confirmation of topology in dissipative many-body quantum chaotic
systems.
A non-perturbative relativistic tight-binding (TB) approximation method
applicable to crystalline material immersed in a magnetic field was developed
in 2015. To apply this method to any material in the magnetic field, the
electronic structure of the material in absence of a magnetic field must be
calculated. In this study, we present the relativistic TB approximation method
for graphene in a zero magnetic field. The Hamiltonian and overlap matrix is
constructed considering the nearest neighbouring atomic interactions between
the $s$ and $p$ valence orbitals, where the relativistic hopping and overlap
integrals are calculated using the relativistic version of the Slater-Koster
table. The method of constructing the Hamiltonian and overlap matrix and the
resulting energy-band structure of graphene in the first Brillouin zone is
presented in this paper. It is found that there is an appearance of a small
band-gap at the $\textbf{K}$ points (also known as the spin-orbit gap) due to
the relativistic effect, whose magnitude is $25$ $\mu$eV.
Fractonic phases are new phases of matter that host excitations with
restricted mobility. We show that a certain class of gapless fractonic phases
are realized as a result of spontaneous breaking of continuous higher-form
symmetries whose conserved charges do not commute with spatial translations. We
refer to such symmetries as nonuniform higher-form symmetries. These symmetries
fall within the standard definition of higher-form symmetries in quantum field
theory, and the corresponding symmetry generators are topological. Worldlines
of particles are regarded as the charged objects of 1-form symmetries, and
mobility restrictions can be implemented by introducing additional 1-form
symmetries whose generators do not commute with spatial translations. These
features are realized by effective field theories associated with spontaneously
broken nonuniform 1-form symmetries. At low energies, the theories reduce to
known higher-rank gauge theories such as scalar/vector charge gauge theories,
and the gapless excitations in these theories are interpreted as
Nambu--Goldstone modes for higher-form symmetries. Due to the nonuniformity of
the symmetry, some of the modes acquire a gap, which is the higher-form
analogue of the inverse Higgs mechanism of spacetime symmetries. The gauge
theories have emergent nonuniform magnetic symmetries, and some of the magnetic
monopoles become fractonic. We identify the 't~Hooft anomalies of the
nonuniform higher-form symmetries and the corresponding bulk symmetry-protected
topological phases. By this method, the mobility restrictions are fully
determined by the choice of the commutation relations of charges with
translations. This approach allows us to view existing (gapless) fracton models
such as the scalar/vector charge gauge theories and their variants from a
unified perspective and enables us to engineer theories with desired mobility
restrictions.
We report a unified theory based on linear response, for analyzing the
longitudinal optical conductivity (LOC) of materials with tilted Dirac cones.
Depending on the tilt parameter $t$, the Dirac electrons have four phases:
untilted, type-I, type-II, and type-III; the Dirac dispersion can be isotropic
or anisotropic; the spatial dimension of the material can be one-, two-, or
three-dimensions (1D, 2D and 3D). The interband LOCs and intraband LOCs in $d$
dimension (with $d\ge2$) are found to scale as $\sigma_{0}\omega^{d-2}$ and
$\sigma_{0}\mu^{d-1}\delta(\omega)$, respectively, where $\omega$ is the
frequency and $\mu$ the chemical potential. The interband LOC vanishes in 1D
due to lack of extra spatial dimension. In contrast, the interband LOCs in 2D
and 3D are nonvanishing and share many similar properties. A universal and
robust fixed point of interband LOCs appears at $\omega=2\mu$ no matter $d=2$
or $d=3$, which can be intuitively understood by the geometric structures of
Fermi surface and energy resonance contour. The intraband LOCs and the carrier
density for 2D and 3D tilted Dirac bands are both closely related to the
geometric structure of Fermi surface and the cutoff of integration. The angular
dependence of LOCs is found to characterize both spatial dimensionality and
band tilting and the constant asymptotic background values of LOC reflect
features of Dirac bands. The LOCs in the anisotropic tilted Dirac cone can be
connected to its isotropic counterpart by a ratio that consists of Fermi
velocities for both 2D and 3D. Most of the findings are universal for tilted
Dirac materials and hence valid for a great many Dirac materials in the spatial
dimensions of physical interest.
The topological classification of electronic band structures is based on
symmetry properties of Bloch eigenstates of single-particle Hamiltonians. In
parallel, topological field theory has opened the doors to the formulation and
characterization of non-trivial phases of matter driven by strong
electron-electron interaction. Even though important examples of topological
Mott insulators have been constructed, the relevance of the underlying
non-interacting band topology to the physics of the Mott phase has remained
unexplored. Here, we show that the momentum structure of the Green's function
zeros defining the ``Luttinger surface" provides a topological characterization
of the Mott phase related, in the simplest description, to the one of the
single-particle electronic dispersion. Considerations on the zeros lead to the
prediction of new phenomena: a topological Mott insulator with an inverted gap
for the bulk zeros must possess gapless zeros at the boundary, which behave as
a form of ``topological antimatter'' annihilating conventional edge states.
Placing band and Mott topological insulators in contact produces distinctive
observable signatures at the interface, revealing the otherwise
spectroscopically elusive Green's function zeros.
We study the motion of charge carriers in curved Dirac materials, in the
presence of a local Fermi velocity. An explicit parameterization of the latter
emerging quantity for a nanoscroll cylindrical geometry is also provided,
together with a discussion of related physical effects and observable
properties.
Quantum Floquet engineering seeks to externally control systems by means of
quantum fields. However, to faithfully capture the physics at arbitrary
coupling, a gauge-invariant description of light-matter interaction is
required, which makes the Hamiltonian highly nonlinear in the photonic
operators. Here we provide a non-perturbative truncation scheme, which is valid
for arbitrary coupling strength. With this framework, we investigate the role
of light-matter correlations, which are absent in systems described by
semiclassical Floquet engineering. We find that even in the high-frequency
regime, their importance can be crucial, in particular for the topological
properties of the system. As an example we show that in an SSH chain coupled to
a cavity, light-matter correlations break chiral symmetry, strongly affecting
the robustness of its edge states. In addition, we show how light-matter
correlations are imprinted in the photonic spectral function, and discuss their
relation with the topology of the photonic bands.
We have studied ferromagnetic metal/topological insulator bilayer system to
understand magnetization dynamics of ferromagnetic metal (FM) in contact with a
topological insulator (TI). At magnetic resonance condition, the precessing
magnetization in the metallic ferromagnet ($Ni_{80}Fe_{20}$) injects spin
current into the topological insulator ($BiSbTe_{1.5}Se_{1.5}$), a phenomenon
known as spin-pumping. Due to the spin pumping effect, fast relaxation in the
ferromagnet results in the broadening of ferromagnetic resonance linewidth
($\Delta H$). We evaluated the parameters like effective Gilbert damping
coefficient ($\alpha_{eff}$), spin-mixing conductance ($g_{eff}^{\uparrow
\downarrow}$) and spin current density ($j_S^0$) to confirm a successful spin
injection due to spin-pumping into the $BiSbTe_{1.5}Se_{1.5}$ layer. TIs embody
a spin-momentum locked surface state that span the bulk band-gap. It can act
differently to the FM magnetization than the other normal metals. To probe the
effect of topological surface state, a systematic low temperature study is
crucial as surface state of TI dominates at lower temperatures. The exponential
growth of $\Delta H$ for all different thickness combination of FM/TI bilayers
and effective Gilbert damping coefficient ($\alpha_{eff}$) with lowering
temperature confirms the prediction that spin chemical bias generated from
spin-pumping induces surface current in TI due to spin-momentum locking. The
hump-like feature of magnetic anisotropy field ($H_K$)of the bilayer around 60K
suggests that the decrease of interfacial in-plane magnetic anisotropy can
result from exchange coupling between the TI surface state and the local
moments of FM layer.
The coherent dynamics of a quantum mechanical two-level system passing
through an anti-crossing of two energy levels can give rise to
Landau-Zener-St\"uckelberg-Majorana (LZSM) interference. LZSM interference
spectroscopy has proven to be a fruitful tool to investigate charge noise and
charge decoherence in semiconductor quantum dots (QDs). Recently, bilayer
graphene has developed as a promising platform to host highly tunable QDs
potentially useful for hosting spin and valley qubits. So far, in this system
no coherent oscillations have been observed and little is known about charge
noise in this material. Here, we report coherent charge oscillations and
$T_2^*$ charge decoherence times in a bilayer graphene double QD. The charge
decoherence times are measured independently using LZSM interference and photon
assisted tunneling. Both techniques yield $T_2^*$ average values in the range
of 400 to 500 ps. The observation of charge coherence allows to study the
origin and spectral distribution of charge noise in future experiments.
A quantum kicked rotor model is one of the promising systems to realize
various Floquet topological phases. We consider a double-kicked rotor model for
a one-dimensional quasi-spin-1/2 Bose-Einstein condensate with spin-dependent
and spin-independent kicks which are implementable for cold atomic experiments.
We theoretically show that the model can realize all the Altland-Zirnbauer
classes with nontrivial topology in one dimension. In the case of class CII, we
show that a pair of winding numbers $(w_0,w_\pi)\in 2\mathbb{Z}\times
2\mathbb{Z}$ featuring the edge states at zero and $\pi$ quasienergy,
respectively, takes various values depending on the strengths of the kicks. We
also find that the winding numbers change to $\mathbb{Z}$ when we break the
time-reversal and particle-hole symmetries by changing the phase of a kicking
lattice. We numerically confirm that the winding numbers can be obtained by
measuring the mean chiral displacement in the long-time limit in the present
case with four internal degrees of freedom. We further propose two feasible
methods to experimentally realize the spin-dependent and spin-independent kicks
required for various topological phases.
Within linear response theory, the absorptive part of highly anisotropic
optical conductivities are analytically calculated for distinct tilts in
two-dimensional (2D) tilted semi-Dirac bands (SDBs). The transverse optical
conductivities always vanish. The interband longitudinal optical conductivities
(LOCs) in 2D tilted SDBs differ qualitatively in the power-law scaling of
$\omega$ as
$\mathrm{Re}\sigma_{\perp}^{\mathrm{IB}}(\omega)\propto\sigma_0\sqrt{\omega}$
and
$\mathrm{Re}\sigma_{\parallel}^{\mathrm{IB}}(\omega)\propto\sigma_0/\sqrt{\omega}$.
By contrast, the intraband LOCs in 2D tilted SDBs depend on $\mu$ in the
power-law scaling as
$\mathrm{Re}\sigma_{\perp}^{\mathrm{D}}(\omega)\propto\sigma_0\mu \sqrt{\mu}$
and
$\mathrm{Re}\sigma_{\parallel}^{\mathrm{D}}(\omega)\propto\sigma_0\mu/\sqrt{\mu}$.
The tilt-dependent behaviors of LOCs could qualitatively characterize distinct
impact of band tilting in 2D tilted SDBs. In particular, for arbitrary tilt $t$
satisfying $0<t\le 2$, the interband LOCs always possess a robust fixed point
at $\omega=2\mu$. The power-law scalings and tilt-dependent behaviors further
dictate significant differences in the asymptotic background values and angular
dependence of LOCs. Our theoretical predictions should be valid for a broad
class of 2D tilted SDB materials, and can also be used to fingerprint 2D tilted
SDB from 2D untilted SDB as well as tilted Dirac bands.
MnBi$_2$Te$_4$, the first confirmed intrinsic antiferromagnetic topological
insulator, has garnered increasing attention in recent years. Here we
investigate the energy correction and lifetime of magnons in MnBi$_2$Te$_4$
caused by magnon-magnon interaction. First, a calculation based on the density
functional theory was performed to get the parameters of the magnetic
Hamiltonian of MnBi$_2$Te$_4$. Subsequently, the perturbation method of
many-body Green's function was employed and the first-order self-energy
[$\Sigma^{(1)}(\bm k)$] and second-order self-energy [$\Sigma^{(2)}(\bm
k,\varepsilon_{\bm k})$] of magnon were obtained. Numerical computations reveal
that the corrections from both $\Sigma^{(1)}(\bm k)$ and $\Sigma^{(2)}(\bm
k,\varepsilon_{\bm k})$ strongly rely on momentum and temperature, with the
energy renormalization near the Brillouin zone (BZ) boundary being
significantly more pronounced than that near the BZ center. Furthermore, our
findings indicate the occurrence of dip structures in the renormalized magnon
spectrum near the $\rm K$ and $\rm M$ points. These dip structures are
determined to be attributed to the influence of $\Sigma^{(2)}(\bm
k,\varepsilon_{\bm k})$.
Recent studies on disorder-induced many-body localization (MBL) in
non-Hermitian quantum systems have attracted great interest. However, the
non-Hermitian disorder-free MBL still needs to be clarified. We consider a
one-dimensional interacting Stark model with nonreciprocal hoppings having
time-reversal symmetry, the properties of which are boundary dependent. Under
periodic boundary conditions (PBCs), such a model exhibits three types of phase
transitions: the real-complex transition of eigenenergies, the topological
phase transition, and the non-Hermitian Stark MBL transition. The real-complex
and topological phase transitions occur at the same point in the thermodynamic
limit but do not coincide with the non-Hermitian Stark MBL transition, which is
quite different from the non-Hermitian disordered cases. By the level
statistics, the system transitions from the Ginibre ensemble (GE) to the
Gaussian orthogonal ensemble (GOE) to the Possion ensemble with the increase of
the linear tilt potential's strength. The real-complex transition of the
eigenvalues is accompanied by the GE-to-GOE transition in the ergodic regime.
Moreover, the second transition of the level statistics corresponds to the
occurrence of non-Hermitian Stark MBL. We demonstrate that the non-Hermitian
Stark MBL is robust and shares many similarities with disorder-induced MBL,
which several existing characteristic quantities of the spectral statistics and
eigenstate properties can confirm. The dynamical evolutions of the entanglement
entropy and the density imbalance can distinguish the real-complex and Stark
MBL transitions. Finally, we find that our system under open boundary
conditions lacks a real-complex transition, and the transition of non-Hermitian
Stark MBL is the same as that under PBCs.
The shift current is part of the second-order optical response of materials
with a close connection to topology. Here we report a sign inversion in the
band-edge shift photoconductivity of the Haldane model when the system
undergoes a topological phase transition. This result is obtained following two
complementary schemes. On one hand, we derive an analytical expression for the
band-edge shift current in a two-band tight-binding model showing that the sign
reversal is driven by the mass term. On the other hand, we perform a numerical
evaluation on a continuum version of the Haldane model. This approach allows us
to include off-diagonal matrix elements of the position operator, which are
discarded in tight-binding models but can contribute significantly to the shift
current. Explicit evaluation of the shift current shows that while the model
predictions remain accurate in the deep tight-binding regime, significant
deviations arise for shallow potential landscapes. Notably, the sign reversal
across the topological phase transition is observed in all regimes, implying it
is a robust effect that could be observable in a wide range of topological
insulators.
Universal scaling laws govern the density of topological defects generated
while crossing an equilibrium continuous phase transition. The Kibble-Zurek
mechanism (KZM) predicts the dependence on the quench time for slow quenches.
By contrast, for fast quenches, the defect density scales universally with the
amplitude of the quench. We show that universal scaling laws apply to dynamic
phase transitions driven by an oscillating external field. The difference in
the energy response of the system to a periodic potential field leads to energy
absorption, spontaneous breaking of symmetry, and its restoration. We verify
the associated universal scaling laws, providing evidence that the critical
behavior of non-equilibrium phase transitions can be described by time-average
critical exponents combined with the KZM. Our results demonstrate that the
universality of critical dynamics extends beyond equilibrium criticality,
facilitating the understanding of complex non-equilibrium systems.
The parton approach for quantum spin liquids gives a transparent description
of low-energy elementary excitations, e.g., spinons and emergent gauge-field
fluctuations. The latter ones are directly coupled to the hopping/pairing of
spinons. By using the fermionic representation of the $U(1)$ Dirac state on the
kagome lattice and variational Monte Carlo techniques to include the Gutzwiller
projection, we analyse the effect of modifying the gauge fields in the spinon
kinematics. In particular, we construct low-energy monopole excitations, which
are shown to be gapless in the thermodynamic limit. States with a finite number
of monopoles or with a finite density of them are also considered, with
different patterns of the gauge fluxes. We show that these chiral states are
not stabilized in the Heisenberg model with nearest-neighbor super-exchange
couplings, and the Dirac state corresponds to the lowest-energy Ansatz within
this family of variational wave functions. Our results support the idea that
spinons with a gapless conical spectrum coexist with gapless monopole
excitations, even for the spin-1/2 case.
The topological Kondo effect is a genuine manifestation of the nonlocality of
Majorana modes. We investigate its out-of-equilibrium signatures in a model
with a Cooper-pair box hosting four of these topological modes, each connected
to a metallic lead. Through an advanced matrix-product-state approach tailored
to study the dynamics of superconductors, we simulate the relaxation of the
Majorana magnetization, which allows us to determine the related Kondo
temperature, and we analyze the onset of electric transport after a quantum
quench of a lead voltage. Our results apply to Majorana Cooper-pair boxes
fabricated in double nanowire devices and provide nonperturbative evidence of
the crossover from weak-coupling states to the strongly correlated topological
Kondo regime. The latter dominates at the superconductor charge degeneracy
points and displays the expected universal fractional zero-bias conductance.
Zigzag nanoribbons hosting the Haldane Chern insulator model are considered.
In this context, an unreported reentrant topological phase, characterized by
the emergence of quasi zero dimensional in-gap states, is discussed. The bound
states, which reside in the gap opened by the hybridization of the
counter-propagating edge modes of the Haldane phase, are localized at the ends
of the strip and are found to be robust against on-site disorder. These
findings are supported by the behavior of the Zak phase over the parameter
space, which exhibits jumps of $\pi$ in correspondence to the phase transitions
between the trivial and the non-trivial phases. The effective mass inversion
leading to the jumps in the Zak phase is interpreted in a low energy framework.
Setups with non-uniform parameters also show topological bound states via the
Jackiw-Rebbi mechanism. All the properties reported are shown to be extremely
sensitive to the strip width.
We present a device architecture of hybrid-edge and dual-gated quantum point
contact. We demonstrate improved electrostatic control over the separation,
position, and coupling of each broken-symmetry compressible strip in graphene.
Via low-temperature magneto-transport measurement, we demonstrate selective
manipulation over the evolution, hybridization, and transmission of arbitrarily
chosen quantum Hall states in the channel. With gate-tunable tunneling
spectroscopy, we characterize the energy gap of each symmetry-broken quantum
Hall state with high resolution on the order of ~0.1 meV.
The search for room-temperature superconductors has been a long-standing goal
in condensed matter physics. In this study, we investigate the electronic and
geometric properties of lead apatite with and without Cu doped within the frame
work of the density functional theory. Based on our calculations, we found that
without the Cu doped the lead apatite shows an insulator character with flat
bands straddle the Fermi level. Once we introduce the O1 vacancies, the flat
bands disappear. Furthermore, we analyze the effects of Cu doping on the
crystal structure and electronic band structure of the material. Our
calculations reveal the presence of one-dimensional channels induced by fully
occupied O1 atoms, that are only 1/4 occupied in the literature, which may play
a crucial role in the realization of room-temperature superconductivity. Based
on our findings, we propose a possible solution to improve the quality of
superconductivity by annealing the material in an oxygen atmosphere. These
results contribute to a better understanding of the unusual properties of
Cu-doped lead apatite and will pave the way for further exploration of its
potential as a room-temperature superconductor.
We study the non-Hermitian (NH) Toda model coupled to fermions through
soliton theory techniques and the realizations of the pseudo-chiral and
pseudo-Hermitian symmetries. The interplay of non-Hermiticity, integrability,
nonlinearity, and topology significantly influence the formation and behavior
of a continuum of bound state modes (CBM) and extended waves in the localized
continuum (ELC). The non-Hermitian soliton-fermion duality, the complex scalar
field topological charges and winding numbers in the spectral topology are
uncovered. The Hermitian bound states/solitons lie on the unit circle $|z|=1$
defined by the uniformization parameter $z \in \IC \backslash \{0\}$ related to
the complex energy eigenvalue, whereas the non-Hermitian bound states/solitons
lie on the complex plane such that $|z| \neq 1$. The biorthogonal Majorana zero
modes, dual to the NH Toda solitons with topological charges $\pm 1$, appear at
the complex-energy point gap and are pinned at zero energy. The regions of
$\IC\backslash \{0\}$ with real eigenvalues are uncovered, and these come in
real pairs $\pm \l_1\, (\l_1 \in \IR)$ preserving the pseudo-chiral symmetry.
Our findings improve the understanding of exotic quantum states, but also paves
the way for future research in harnessing non-Hermitian phenomena for
topological quantum computation, as well as the exploration of integrability
and NH solitons in the theory of topological phases of matter.the theory of
topological phases of matter.
Motivated by a recent experiment [Kapfer et. al., Science {\bf 381}, 677
(2023)], we analyze the structural effects and low-energy physics of a bent
nanoribbon placed on top of graphene, which creates a gradually changing
moir\'e pattern. By means of a classical elastic model we derive the strains in
the ribbon and we obtain its spectrum with a scaled tight-binding model. The
size of the bent region is determined by the balance between elastic and van
der Waals energy, and different regimes are identified. Near the clamped edge,
strong strains and small angles leads to one-dimensional channels. Near the
bent edge, a long region behaves like magic angle twisted bilayer graphene
(TBG), showing a sharp peak in the density of states, mostly isolated from the
rest of the spectrum. We also calculate the band topology along the ribbon and
we find that it is stable for large intervals of strains an twist angles.
Together with the experimental observations, these results show that the bent
nanoribbon geometry is ideal for exploring superconductivity and correlated
phases in TBG in the very sought-after regime of ultra-low twist angle
disorder.
Remarkable recent experiments on the moir\'e structure formed by pentalayer
rhombohedral graphene aligned with a hexagonal Boron-Nitride substrate report
the discovery of a zero field fractional quantum hall effect. These
``(Fractional) Quantum Anomalous Hall" ((F)QAH) phases occur for one sign of a
perpendicular displacement field, and correspond, experimentally, to full or
partial filling of a valley polarized Chern-$1$ band. Such a band is absent in
the non-interacting band structure. Here we show that electron-electron
interactions play a crucial role, and present microscopic theoretical
calculations demonstrating the emergence of a nearly flat, isolated, Chern-$1$
band and FQAH phases in this system. We also study the four and six-layer
analogs and identify parameters where a nearly flat isolated Chern-$1$ band
emerges which may be suitable to host FQAH physics.
The standard theoretical framework for fractional quantum anomalous Hall
effect (FQAH) assumes an isolated flat Chern band in the single particle level.
In this paper we challenges this paradigm for the FQAH recently observed in the
pentalayer rhombohedral stacked graphene aligned with hexagon boron nitride
(hBN). We show that the external moir\'e superlattice potential is simply a
perturbation in a model with continuous translation symmetry. Through Hartree
Fock calculation, we find that interaction opens a sizable remote band gap,
resulting an isolated narrow $C=1$ Chern band at filling $\nu=1$. From exact
diagonalization (ED) we identify FQAH phases at various fillings. But they
exist also in the calculations without any external moir\'e potential. We
suggest that the QAH insulator at $\nu=1$ should be viewed as an interaction
driven QAH-Wigner crystal, which is then pinned by a small moir\'e potential.
In the second part we propose a new setup with Coulomb generated moir\'e
superlattice. For example, we separate $n$-layer graphene and twisted bilayer
graphene (TBG) with a thin hBN and imprint the superlattice of the TBG to the
$n$-layer graphene. Now the superlattice potential is controlled by the
thickness $d$ of the hBN and the superlattice period is controlled by the twist
angle of the TBG. Overall in both setups the $C=1$ QAH-Wigner crystal is robust
with a crystal period around $10\mathrm{nm}$ in 4-layer, 5-layer, 6-layer and
7-layer graphene systems. Our work suggests a new direction to explore the
interplay of topology and FQAH with spontaneous Wigner crystal formation in the
vanishing moir\'e potential limit.
Ultraclean graphene at charge neutrality hosts a quantum critical Dirac fluid
of interacting electrons and holes. Interactions profoundly affect the charge
dynamics of graphene, which is encoded in the properties of its collective
modes: surface plasmon polaritons (SPPs). The group velocity and lifetime of
SPPs have a direct correspondence with the reactive and dissipative parts of
the tera-Hertz (THz) conductivity of the Dirac fluid. We succeeded in tracking
the propagation of SPPs over sub-micron distances at femto-second (fs) time
scales. Our experiments uncovered prominent departures from the predictions of
the conventional Fermi-liquid theory. The deviations are particularly strong
when the densities of electrons and holes are approximately equal. Our imaging
methodology can be used to probe the electromagnetics of quantum materials
other than graphene in order to provide fs-scale diagnostics under
near-equilibrium conditions.
Lorentz symmetry appears as a quite robust feature of the strongly
interacting Dirac materials even though the lattice interactions break such a
symmetry. We here demonstrate that the Lorentz symmetry is restored at the
quantum-critical point (QCP) separating the tilted Dirac semimetal, breaking
this symmetry already at the noninteracting level, from a gapped $s-$wave
superconducting instability. To this end, we employ a one-loop
$\epsilon=(3-D)-$expansion close to the $D=3$ upper critical dimension of the
corresponding Gross-Neveu-Yukawa field theory. In particular, we show that the
tilt parameter is irrelevant and ultimately vanishes at the QCP separating the
two phases. In fact, as we argue here, such a Lorentz symmetry restoration may
be generic for the strongly interacting tilted Dirac semimetals, irrespective
of whether they feature mirror-symmetric or mirror-asymmetric tilting, and is
also insensitive to whether the instability represents an insulator or a gapped
superconductor. The proposed scenario can be tested in the quantum Monte Carlo
simulations of the interacting tilted Dirac fermion lattice models.
We present a study of the 3d O(2) non-linear $\sigma$-model on the lattice,
which exhibits topological defects in the form of vortices. They tend to
organize into vortex lines that bear close analogies with global cosmic
strings. Therefore, this model serves as a testbed for studying the dynamics of
topological defects. It undergoes a second order phase transition, hence it is
appropriate for investigating the Kibble-Zurek mechanism. In this regard, we
explore the persistence of topological defects when the temperature is rapidly
reduced from above to below the critical temperature; this cooling (or
"quenching") process takes the system out of equilibrium. We probe a wide range
of inverse cooling rates $\tau_{\rm Q}$ and final temperatures, employing
distinct Monte Carlo algorithms. The results consistently show that the density
of persisting topological defects follows a power-law in $\tau_{\rm Q}$, in
agreement with Zurek's conjecture. On the other hand, at this point our results
do not confirm Zurek's prediction for the exponent in this power-law, but its
final test is still under investigation.

Date of feed: Mon, 27 Nov 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) **Emergent chiral metal near a Kondo breakdown quantum phase transition. (arXiv:2311.13641v1 [cond-mat.str-el])**

Tom Drechsler, Matthias Vojta

**Qudit Stabilizer Codes, CFTs, and Topological Surfaces. (arXiv:2311.13680v1 [hep-th])**

Matthew Buican, Rajath Radhakrishnan

**Fractional Quantum Hall State at Filling Factor $\nu=1/4$ in Ultra-High-Quality GaAs 2D Hole Systems. (arXiv:2311.13689v1 [cond-mat.mes-hall])**

Chengyu Wang, A. Gupta, S. K. Singh, P. T. Madathil, Y. J. Chung, L. N. Pfeiffer, K. W. Baldwin, R. Winkler, M. Shayegan

**Nonrelaxational FMR peak broadening in spatially inhomogeneous films. (arXiv:2311.13733v1 [cond-mat.mes-hall])**

Victor A. L'vov, Julia Kharlan, Vladimir O. Golub

**The valleytronic topological filters in silicene-like inner-edge systems. (arXiv:2311.13758v1 [cond-mat.mes-hall])**

Hang Xie, Xiao-Long Lü, Jia-En Yang

**B63: the most stable bilayer structure with dual aromaticity. (arXiv:2311.13772v1 [cond-mat.mtrl-sci])**

Jinhuang Chen, Rui Liao, Linwei Sai, Xue Wu, Jijun Zhao

**Quantum Hall and Light Responses in a 2D Topological Semimetal. (arXiv:2311.13922v1 [cond-mat.mes-hall])**

Sariah Al Saati, Karyn Le Hur

**Semiclassical analysis of two-scale electronic Hamiltonians for twisted bilayer graphene. (arXiv:2311.14011v1 [math-ph])**

Eric Cancès, Long Meng

**Massive topological edge channels in three-dimensional topological materials induced by extreme surface anisotropy. (arXiv:2311.14069v1 [cond-mat.mes-hall])**

Fengfeng Zhu, Chenqiang Hua, Xiao Wang, Lin Miao, Yixi Su, Makoto Hashimoto, Donghui Lu, Zhi-Xun Shen, Jin-Feng Jia, Yunhao Lu, Dandan Guan, Dong Qian

**Two dimensional quantum lattice models via mode optimized hybrid CPU-GPU density matrix renormalization group method. (arXiv:2311.14106v1 [cond-mat.str-el])**

Andor Menczer, Kornél Kapás, Miklós Antal Werner, Örs Legeza

**Cosmic string influence on a 2D hydrogen atom and its relationship with the Rytova-Keldysh logarithmic approximation in semiconductors. (arXiv:2311.14144v1 [quant-ph])**

Frankbelson dos S. Azevedo, Izael A. Lima, Gallileu Genesis, Rodolfo Casana, Edilberto O. Silva

**Bulk-edge correspondence for the nonlinear eigenvalues problem of the Haldane model. (arXiv:2311.14229v1 [cond-mat.dis-nn])**

Shujie Cheng, Yonghua Jiang, Gao Xianlong

**Identification of odd-frequency superconducting pairing in Josephson junctions. (arXiv:2311.14297v1 [cond-mat.mes-hall])**

Subhajit Pal, Aabir Mukhopadhyay, Sourin Das

**Theory of fractional Chern insulator states in pentalayer graphene moir\'e superlattice. (arXiv:2311.14368v1 [cond-mat.str-el])**

Zhongqing Guo, Xin Lu, Bo Xie, Jianpeng Liu

**Electrically tunable correlated domain wall network in twisted bilayer graphene. (arXiv:2311.14384v1 [cond-mat.mes-hall])**

Hao-Chien Wang, Chen-Hsuan Hsu

**Commensurate-incommensurate transition in frustrated Wigner crystals. (arXiv:2311.14396v1 [cond-mat.quant-gas])**

Raphaël Menu, Jorge Yago Malo, Vladan Vuletić, Maria Luisa Chiofalo, Giovanna Morigi

**Effect of the depolarizing field on the domain structure of an improper ferroelectric. (arXiv:2311.14429v1 [cond-mat.mtrl-sci])**

Aaron Merlin Müller, Amadé Bortis, Manfred Fiebig, Thomas Lottermoser

**Correlation between microstructural deformation mechanisms and acoustic parameters on a cold-rolled Cu30Zn brass. (arXiv:2311.14430v1 [cond-mat.mtrl-sci])**

Maria Sosa, Linton Carvajal, Vicente Salinas, Fernando Lund, Claudio Aguilar, Felipe Castro

**Solid-that-flows picture of glass-forming liquids. (arXiv:2311.14460v1 [cond-mat.soft])**

Jeppe C. Dyre

**Multiple superconducting phases driven by pressure in the topological insulator GeSb4Te7. (arXiv:2311.14472v1 [cond-mat.supr-con])**

W. Zhou, B. Li, Y. Shen, J. J. Feng, C. Q. Xu, H. T. Guo, Z. He, B. Qian, Ziming Zhu, Xiaofeng Xu

**Back-action supercurrent diodes. (arXiv:2311.14503v1 [cond-mat.mes-hall])**

Daniel Margineda, Alessandro Crippa, Elia Strambini, Yuri Fukaya, Maria Teresa Mercaldo, Carmine Ortix, Mario Cuoco, Francesco Giazotto

**Topological quantum thermometry. (arXiv:2311.14524v1 [quant-ph])**

Anubhav Kumar Srivastava, Utso Bhattacharya, Maciej Lewenstein, Marcin Płodzień

**Ground states of one-dimensional dipolar lattice bosons at unit filling. (arXiv:2311.14606v1 [cond-mat.quant-gas])**

Mateusz Łącki, Henning Korbmacher, G. A. Domínguez-Castro, Jakub Zakrzewski, Luis Santos

**Emergent Topology in Many-Body Dissipative Quantum Chaos. (arXiv:2311.14640v1 [cond-mat.str-el])**

Antonio M. García-García, Lucas Sá, Jacobus J. M. Verbaarschot, Can Yin

**Relativistic Tight-Binding Model for Hexagonal Lattice: Application to Graphene. (arXiv:2204.06836v3 [cond-mat.mtrl-sci] UPDATED)**

Rohin Sharma, Amit Shrestha, Masahiko Higuchi, Katsuhiko Higuchi, Dipendra B. Hamal

**A symmetry principle for gauge theories with fractons. (arXiv:2207.00854v3 [cond-mat.str-el] UPDATED)**

Yuji Hirono, Minyoung You, Stephen Angus, Gil Young Cho

**Effects of spatial dimensionality and band tilting on the longitudinal optical conductivities in Dirac bands. (arXiv:2210.10410v2 [cond-mat.mes-hall] UPDATED)**

Jian-Tong Hou, Chang-Xu Yan, Chao-Yang Tan, Zhi-Qiang Li, Peng Wang, Hong Guo, Hao-Ran Chang

**Mott insulators with boundary zeros. (arXiv:2301.05588v2 [cond-mat.str-el] UPDATED)**

Niklas Wagner, Lorenzo Crippa, Adriano Amaricci, Philipp Hansmann, Marcel Klett, Elio König, Thomas Schäfer, Domenico Di Sante, Jennifer Cano, Andrew Millis, Antoine Georges, Giorgio Sangiovanni

**Dirac equation in curved spacetime: the role of local Fermi velocity. (arXiv:2301.12952v3 [cond-mat.mes-hall] UPDATED)**

B. Bagchi, A. Gallerati, R. Ghosh

**Light-matter correlations in Quantum Floquet engineering. (arXiv:2302.12290v2 [cond-mat.mes-hall] UPDATED)**

Beatriz Pérez-González, Gloria Platero, Álvaro Gómez-León

**Experimental investigation of the effect of topological insulator on the magnetization dynamics of ferromagnetic metal: $BiSbTe_{1.5}Se_{1.5}$ and $Ni_{80}Fe_{20}$ heterostructure. (arXiv:2303.07025v2 [cond-mat.mes-hall] UPDATED)**

Sayani Pal, Soumik Aon, Subhadip Manna, Sambhu G Nath, Kanav Sharma, Chiranjib Mitra

**Coherent Charge Oscillations in a Bilayer Graphene Double Quantum Dot. (arXiv:2303.10119v4 [cond-mat.mes-hall] UPDATED)**

Katrin Hecker, Luca Banszerus, Aaron Schäpers, Samuel Möller, Anton Peters, Eike Icking, Kenji Watanabe, Takashi Taniguchi, Christian Volk, Christoph Stampfer

**Designing nontrivial one-dimensional Floquet topological phases using a spin-1/2 double-kicked rotor. (arXiv:2303.13982v2 [cond-mat.quant-gas] UPDATED)**

Yusuke Koyama, Kazuya Fujimoto, Shuta Nakajima, Yuki Kawaguchi

**Highly anisotropic optical conductivities in two-dimensional tilted semi-Dirac bands. (arXiv:2303.18155v2 [cond-mat.mes-hall] UPDATED)**

Chang-Xu Yan, Chao-Yang Tan, Hong Guo, Hao-Ran Chang

**Magnon-magnon interaction in monolayer MnBi$_2$Te$_4$. (arXiv:2304.09637v3 [cond-mat.str-el] UPDATED)**

Yiqun Liu, Liangjun Zhai, Songsong Yan, Di Wang, Xiangang Wan

**From Ergodicity to Many-Body Localization in a One-Dimensional Interacting Non-Hermitian Stark System. (arXiv:2305.13636v3 [cond-mat.dis-nn] UPDATED)**

Jinghu Liu, Zhihao Xu

**Shift photoconductivity in the Haldane model. (arXiv:2305.17035v2 [cond-mat.mes-hall] UPDATED)**

Javier Sivianes (1), Julen Ibañez-Azpiroz (1 and 2) ((1) Centro de Física de Materiales (CSIC-UPV/EHU), Donostia-San Sebastián, Spain, (2) Ikerbasque Foundation, Bilbao, Spain)

**Universal defect density scaling in an oscillating dynamic phase transition. (arXiv:2306.03803v4 [cond-mat.stat-mech] UPDATED)**

Wei-can Yang, Makoto Tsubota, Adolfo del Campo, Hua-Bi Zeng

**Piercing the Dirac spin liquid: From a single monopole to chiral states. (arXiv:2307.01149v2 [cond-mat.str-el] UPDATED)**

Sasank Budaraju, Yasir Iqbal, Federico Becca, Didier Poilblanc

**The topological Kondo model out of equilibrium. (arXiv:2307.03773v2 [cond-mat.str-el] UPDATED)**

Matteo M. Wauters, Chia-Min Chung, Lorenzo Maffi, Michele Burrello

**Emerging topological bound states in Haldane model zigzag nanoribbons. (arXiv:2307.14771v2 [cond-mat.mes-hall] UPDATED)**

Simone Traverso, Maura Sassetti, Niccolò Traverso Ziani

**Selective Manipulation and Tunneling Spectroscopy of Broken-Symmetry Quantum Hall States in a Hybrid-edge Quantum Point Contact. (arXiv:2307.15728v3 [cond-mat.mes-hall] UPDATED)**

Wei Ren, Xi Zhang, Jaden Ma, Xihe Han, Kenji Watanabe, Takashi Taniguchi, Ke Wang

**The 1/4 occupied O atoms induced ultraflat band and the one dimensional channels in the Pb$_{10-x}$Cu$_{x}$(PO$_4$)$_{6}$O$_{4}$ (x=0,0.5) crystal. (arXiv:2308.03218v4 [cond-mat.supr-con] UPDATED)**

Kun Tao, Rongrong Chen, Lei Yang, Jin Gao, Desheng Xue, Chenglong Jia

**Biorthogonal Majorana zero modes, extended waves in continuum of bound states and non-Hermitian Toda soliton-fermion duality. (arXiv:2310.03215v2 [hep-th] UPDATED)**

Harold Blas

**Designing Moir\'e Patterns by Bending. (arXiv:2310.13743v2 [cond-mat.mes-hall] UPDATED)**

Pierre A. Pantaleón, Héctor Sainz-Cruz, Francisco Guinea

**Theory of fractional quantum anomalous Hall phases in pentalayer rhombohedral graphene moir\'e structures. (arXiv:2311.03445v2 [cond-mat.str-el] UPDATED)**

Zhihuan Dong, Adarsh S. Patri, T. Senthil

**Fractional quantum anomalous Hall effects in rhombohedral multilayer graphene in the moir\'eless limit and in Coulomb imprinted superlattice. (arXiv:2311.04217v2 [cond-mat.str-el] UPDATED)**

Boran Zhou, Hui Yang, Ya-Hui Zhang

**Electronic interactions in Dirac fluids visualized by nano-terahertz spacetime mapping. (arXiv:2311.11502v2 [cond-mat.str-el] UPDATED)**

Suheng Xu, Yutao Li, Rocco A. Vitalone, Ran Jing, Aaron J. Sternbach, Shuai Zhang, Julian Ingham, Milan Delor, James. W. McIver, Matthew Yankowitz, Raquel Queiroz, Andrew J. Millis, Michael M. Fogler, Cory R. Dean, James Hone, Mengkun Liu, D.N. Basov

**Tilted Dirac superconductor at quantum criticality: Restoration of Lorentz symmetry. (arXiv:2311.12797v2 [cond-mat.supr-con] UPDATED)**

Pablo Reiser, Vladimir Juricic

**Non-equilibrium dynamics of topological defects in the 3d O(2) model. (arXiv:2311.13074v1 [hep-lat] CROSS LISTED)**

Edgar López-Contreras, Jaime Fabián Nieto Castellanos, Elías Natanael Polanco-Euán, Wolfgang Bietenholz

Found 1 papers in acs-nano

Date of feed: Sun, 26 Nov 2023 14:12:36 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] Molybdenum Chloride Nanostructures with Giant Lattice Distortions Intercalated into Bilayer Graphene**

Qiunan Liu, Yung-Chang Lin, Silvan Kretschmer, Mahdi Ghorbani-Asl, Pablo Solís-Fernández, Ming-Deng Siao, Po-Wen Chiu, Hiroki Ago, Arkady V. Krasheninnikov, and Kazu SuenagaACS NanoDOI: 10.1021/acsnano.3c06958

Found 3 papers in comm-phys Communications Physics, Published online: 24 November 2023; doi:10.1038/s42005-023-01462-z **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 and high-performance nonreciprocal extraordinary optical transmission from a guided mode to free-space radiation**

Kosmas L. Tsakmakidis

**Author Correction: Spontaneous superconducting diode effect in non-magnetic Nb/Ru/Sr _{2}RuO_{4} topological junctions**

Yoshiteru Maeno

Communications Physics, Published online: 22 November 2023; doi:10.1038/s42005-023-01448-x

Author Correction: Spontaneous superconducting diode effect in non-magnetic Nb/Ru/SrCommunications Physics, Published online: 21 November 2023; doi:10.1038/s42005-023-01461-0 Topological insulators are bulk insulators with conducting zero-energy edge states conventionally predicted by topological indices, such as winding numbers in one-dimensional lattices. Here, the authors use the Jackiw-Rebbi theory to reveal that the number of topologically protected zero-energy states can be higher than the winding number. |