Found 43 papers in cond-mat We introduce the concept of ``quantum geometric nesting'' (QGN) to
characterize the idealized ordering tendencies of certain flat-band systems
implicit in the geometric structure of the flat-band subspace. Perfect QGN
implies the existence of an infinite class of local interactions that can be
explicitly constructed and give rise to solvable ground states with various
forms of possible fermion bi-linear order, including flavor ferromagnetism,
density waves, and superconductivity. For the ideal Hamiltonians constructed in
this way, we show that certain aspects of the low-energy spectrum can also be
exactly computed including, in the superconducting case, the phase stiffness.
Examples of perfect QGN include flat bands with certain symmetries (e.g. chiral
or time-reversal), and non-symmetry-related cases exemplified with an
engineered model for pair-density-wave. Extending this approach, we obtain
exact superconducting ground states with nontrivial pairing symmetry.
In this short note we use the geometric approach to (topological) field
theory to address the question: Does an odd number of quantum mechanical
fermions make sense?
In the last decade, graphene has become an exciting platform for electron
optical experiments, in many aspects superior to conventional two-dimensional
electron gases (2DEGs). A major advantage, besides the ultra-large mobilities,
is the fine control over the electrostatics, which gives the possibility of
realising gap-less and compact p-n interfaces with high precision. The latter
host non-trivial states, \eg, snake states in moderate magnetic fields, and
serve as building blocks of complex electron interferometers. Thanks to the
Dirac spectrum and its non-trivial Berry phase, the internal (valley and
sublattice) degrees of freedom, and the possibility to tailor the band
structure using proximity effects, such interferometers open up a completely
new playground based on novel device architectures. In this review, we
introduce the theoretical background of graphene electron optics, fabrication
methods used to realise electron-optical devices, and techniques for
corresponding numerical simulations. Based on this, we give a comprehensive
review of ballistic transport experiments and simple building blocks of
electron optical devices both in single and bilayer graphene, highlighting the
novel physics that is brought in compared to conventional 2DEGs. After
describing the different magnetic field regimes in graphene p-n junctions and
nanostructures, we conclude by discussing the state of the art in
graphene-based Mach-Zender and Fabry-Perot interferometers.
We have implemented a complex network description for metallic glasses, able
to predict the elasto-plastic regime, the location of shear bands and the
statistics that controls the plastic events that originate in the material due
to a deformation process. By means of molecular dynamics simulations, we
perform a shear deformation test, obtaining the stress-strain curve for CuZr
metallic glass samples. The atomic configurations of the metallic glass are
mapped to a graph, where a node represents an atom whose stress/strain is above
a certain threshold, and edges are connections between existing nodes at
consecutive timesteps in the simulation. We made a statistical study of some
physical descriptors such as shear stress, shear strain, volumetric strain and
non-affine displacement to use them as construction tools for complex networks.
We have calculated their probability density functions, skewness, kurtosis and
gini coefficient to analyze the inequality of the distributions. We study the
evolution of the resulting complex network, by computing topological metrics
such as degree, clustering coefficient, betweenness and closeness centrality as
a function of the strain. We have obtained correlations between the physical
phenomena produced by the deformation with the data recorded by these metrics.
By means the visual representation of the networks, we have also found direct
correlations between metrics and the local atomic shear strain, so that they
are able to predict the location of shear bands, as well as the formation of
highly connected and interacting communities, which we interpret as shear
transformation zones. Our results suggest that the complex network approach has
interesting capabilities for the description of mechanical properties of
metallic glasses.
Nanostructures exhibit unusual properties due to the dominance of quantum
mechanical effects. In addition, the geometry of a nanostructure can have a
strong influence on its physical properties. Using the tight-binding (TB) and
force-constant (FC) approaches with the help of the non-equilibrium Green's
function (NEGF) method, the transport and thermoelectric properties of
cross-shaped (X-shaped) composite heterostructures are studied in two cases:
Mixed graphene and h-BN (HETX-CBN) and all graphene (HETX-C) cross-shaped
structures. Our numerical results show that an X-shaped structure helps to
manipulate its electronic and phononic properties. The transport energy gap can
be tuned in the range of ~0.8 eV by changing one arm width. Due to the drastic
decrease in the electronic conductance of HETX-CBN and the dominance of the
phononic thermal conductance, the ZT performance is degraded despite the high S
value (in the order of meV). However, HETX-C has better ZT performance due to
better electronic conductance and lower phononic/electronic thermal ratio, it
can enhance the ZT ~2.5 times compared to that of zigzag graphene nanoribbon.
The thermoelectric properties of the system can be tuned by controlling the
size of the arms of the device and the type of its atoms.
In this thesis we investigate the instabilities of superfluids at finite
superflow by means of a hydrodynamical approach. We find that at a finite value
of the background superfluid velocity a hydrodynamic collective mode crosses to
the upper half complex frequency plane, thereby signalling a dynamical
instability. At the same time, however, this instability is also thermodynamic,
as its onset is controlled by one of the second derivatives of the free energy
changing sign. We carry out our analysis in two main setups: the "probe limit",
where the fluctuations of the temperature and the normal fluid's velocity are
frozen, and a complete approach, which includes them. In both cases we test our
results with the help of gauge-gravity duality, finding good agreement between
the hydrodynamic modes of the boundary theory and the quasinormal modes of the
gravity theory. Our criterion for the onset of the instability, which is
formulated in a model-independent way, applies to interacting systems
irrespective of the strength of interactions, does not rely on boost invariance
and does not assume any specific quantum statistics. As a final check, we also
show that it yields the Landau critical velocity for Galilean superfluids with
Bose-Einstein quasiparticles.
Observations of emergent quantum phases in twisted bilayer graphene prompted
a flurry of activities in van-der-Waals (vdW) materials beyond graphene. Most
current twisted experiments use a so-called tear-and-stack method using a
polymer called PPC. However, despite the clear advantage of the current PPC
tear-and-stack method, there are also technical limitations, mainly a limited
number of vdW materials that can be studied using this PPC-based method. This
technical bottleneck has been preventing further development of the exciting
field beyond a few available vdW samples. To overcome this challenge and
facilitate future expansion, we developed a new tear-and-stack method using a
strongly adhesive polycaprolactone (PCL). With similar angular accuracy, our
technology allows fabrication without a capping layer, facilitating surface
analysis and ensuring inherently clean interfaces and low operating
temperatures. More importantly, it can be applied to many other vdW materials
that have remained inaccessible with the PPC-based method. We present our
results on twist homostructures made with a wide choice of vdW materials - from
two well-studied vdW materials (graphene and MoS$_2$) to the first-ever
demonstrations of other vdW materials (NbSe$_2$, NiPS$_3$, and Fe$_3$GeTe$_2$).
Therefore, our new technique will help expand $moir\acute{e}$ physics beyond
few selected vdW materials and open up more exciting developments.
Superlattice potential modulation can produce flat minibands in
Bernal-stacked bilayer graphene. In this work we study how band topology and
interaction-induced symmetry-broken phases in this system are controlled by
tuning the displacement field and the shape and strength of the superlattice
potential. We use an analytic perturbative analysis to demonstrate that
topological flat bands are favored by a honeycomb-lattice-shaped potential, and
numerics to show that the robustness of topological bands depends on both the
displacement field strength and the periodicity of the superlattice potential.
At integer fillings of the topological flat bands, the strength of the
displacement field and the superlattice potential tune phase transitions
between quantum anomalous Hall insulator, trivial insulator, and metallic
states. We present mean-field phase diagrams in a gate voltage parameter space
at filling factor $\nu=1$, and discuss the prospects of realizing quantum
anomalous Hall insulators and fractional Chern insulators when the superlattice
potential modulation is produced by dielectric patterning or adjacent moir\'e
materials.
Topologically ordered phases of matter elude Landau's symmetry-breaking
theory, featuring a variety of intriguing properties such as long-range
entanglement and intrinsic robustness against local perturbations. Their
extension to periodically driven systems gives rise to exotic new phenomena
that are forbidden in thermal equilibrium. Here, we report the observation of
signatures of such a phenomenon -- a prethermal topologically ordered time
crystal -- with programmable superconducting qubits arranged on a square
lattice. By periodically driving the superconducting qubits with a surface-code
Hamiltonian, we observe discrete time-translation symmetry breaking dynamics
that is only manifested in the subharmonic temporal response of nonlocal
logical operators. We further connect the observed dynamics to the underlying
topological order by measuring a nonzero topological entanglement entropy and
studying its subsequent dynamics. Our results demonstrate the potential to
explore exotic topologically ordered nonequilibrium phases of matter with noisy
intermediate-scale quantum processors.
We consider a one-dimensional classical ferromagnetic Ising model when it is
quenched from a low temperature to zero temperature in finite time using
Glauber or Kawasaki dynamics. Most of the previous work on finite-time quenches
assume that the system is initially in equilibrium and focus on the excess
defect density at the end of the quench which decays algebraically in quench
time with Kibble-Zurek exponent. Here we are interested in understanding the
conditions under which the Kibble-Zurek scalings do not hold and in elucidating
the full dynamics of the defect density. We find that depending on the initial
conditions and quench time, the dynamics of the defect density can be
characterized by coarsening and/or the standard finite-time quench dynamics
involving adiabatic evolution and Kibble-Zurek dynamics; the time scales for
crossover between these dynamical phases are determined by coarsening time and
stationary state relaxation time. As a consequence, the defect density at the
end of the quench is either a constant or decays following coarsening laws or
Kibble-Zurek scaling. For the Glauber chain, we formulate a low temperature
scaling theory and find exact expressions for the final defect density for
various initial conditions. For the Kawasaki chain where the dynamic exponents
for coarsening and stationary state dynamics are different, we verify the above
findings numerically and also examine the effect of unequal dynamic exponents.
This work examines self-mixing in active nematics, a class of fluids in which
mobile topological defects drive chaotic flows in a system comprised of
biological filaments and molecular motors. We present experiments that
demonstrate how geometrical confinement can influence the braiding dynamics of
the defects. Notably, we show that confinement in cardioid-shaped wells leads
to realization of the golden braid, a maximally efficient mixing state of
exactly three defects with no defect creation or annihilation. We characterize
the golden braid state using different measures of topological entropy and the
Lyapunov exponent. In particular, topological entropy measured from the
stretching rate of material lines agrees well with an analytical computation
from braid theory. Increasing the size of the confining cardioid produces a
transition from the golden braid, to the fully chaotic active turbulent state.
Low-temperature scanning probe microscopes (SPMs) are critical for the study
of quantum materials and quantum information science. Due to the rising costs
of helium, cryogen-free cryostats have become increasingly desirable. However,
they typically suffer from comparatively worse vibrations than cryogen-based
systems, necessitating the understanding and mitigation of vibrations for SPM
applications. Here we demonstrate the construction of two cryogen-free dilution
refrigerator SPMs with minimal modifications to the factory default and we
systematically characterize their vibrational performance. We measure the
absolute vibrations at the microscope stage with geophones, and use both
microwave impedance microscopy and a scanning single electron transistor to
independently measure tip-sample vibrations. Additionally, we implement
customized filtering and thermal anchoring schemes, and characterize the
cooling power at the scanning stage and the tip electron temperature. This work
serves as a reference to researchers interested in cryogen-free SPMs, as such
characterization is not standardized in the literature or available from
manufacturers.
Experimental investigations of spin-charge interconversion in magnetic
bilayers comprising a ferromagnet adjacent to a topological insulator have
reported scattered results on the spin-charge and charge-spin conversion
efficiency. Attempting to reconcile these contradicting experimental results,
we develop a phenomenological theory of spin-charge interconversion accounting
for both interfacial interconversion through the spin galvanic effect, also
called the Rashba-Edelstein effect, as well as bulk interconversion via the
spin Hall effect. We find that the spin current leakage into the nonmagnetic
metal plays a central role during the spin-to-charge and charge-to-spin
conversion, leading to dissymmetric interconversion processes. In particular,
spin-to-charge conversion is much less sensitive to the spin current absorption
in the nonmagnetic metal than charge-to-spin conversion. This suggests that
spin pumping is a more trustable technique to extract the interfacial Rashba
parameter than spin-orbit torque.
We study the exciton condensation in the heterostructures where the electron
layer and hole layer formed by gapped chiral Fermion (GCF) systems are
separately gated. High-angular momentum such as p- and d-wave like excitonic
pairing may emerge when the gap of the GCF systems is small compared to the
Fermi energy, and the chiral winding number of the electrons and holes are the
same. This is a result of the non-trivial band geometry and can be linked to
the Berry curvature when projected onto the Fermi surface. In realistic
systems, we propose that staggered graphene and magnetic topological surface
states are promising candidates for realizing p-wave exciton superfluid, and
anomalous Hall conductivity can be used as a signature in experiments.
Quantum-Hall--Superconductor hybrids have been predicted to exhibit various
types of topological order, providing possible platforms for intrinsically
fault-tolerant quantum computing. In this paper, we develop a formulation to
construct this hybrid system on a sphere, a useful geometry for identifying
topologically ordered states due to its compact and contractible nature. As a
preliminary step using this framework, we investigate disorder effects on the
Rashba-coupled quantum Hall system combined with the type-II superconductor. By
diagonalizing the BdG Hamiltonian projected into a Rashba-coupled Landau level,
we demonstrate the emergence of a topological superconducting phase resulting
from disorders and proximity-induced pairing. Distinctive gapless modes appear
in the real-space entanglement spectrum, which is consistent with topological
superconductivity.
We discuss the derivation of the electrodynamics of superconductors coupled
to the electromagnetic field from a Lorentz-invariant bosonic model of Cooper
pairs. Our results are obtained at zero temperature where, according to the
third law of thermodynamics, the entropy of the system is zero. In the
nonrelativistic limit we obtain a Galilei-invariant superconducting system
which differs with respect to the familiar Schr\"odinger-like one. From this
point of view, there are similarities with the Pauli equation of fermions which
is derived from the Dirac equation in the nonrelativistic limit and has a
spin-magnetic field term in contrast with the Schr\"odinger equation. One of
the peculiar effects of our model is the decay of a static electric field
inside a superconductor exactly with the London penetration length. In
addition, our theory predicts a modified D'Alembert equation for the massive
electromagnetic field also in the case of nonrelativistic superconducting
matter. We emphasize the role of the Nambu-Goldstone phase field which is
crucial to obtain the collective modes of the superconducting matter field. In
the special case of a nonrelativistic neutral superfluid we find a gapless
Bogoliubov-like spectrum, while for the charged superfluid we obtain a
dispersion relation that is gapped by the plasma frequency.
Higher-order topological insulators and semimetals, which generalize the
conventional bulk-boundary correspondence, have attracted extensive research
interest. Among them, higher-order Weyl semimetals feature two-fold linear
crossing points in three-dimensional (3D) momentum space, 2D Fermi-arc surface
states, and 1D hinge states. Higher-order nodal-point semimetals possessing
Weyl points or Dirac points have been implemented. However, higher-order
nodal-line or nodal-surface semimetals remain to be further explored in
experiments in spite of many previous theoretical efforts. In this work, we
realize a second-order nodal-line semimetal in 3D phononic crystals. The bulk
nodal lines, 2D drumhead surface states guaranteed by Zak phases, and 1D flat
hinge states attributed to kz-dependent quadrupole moments, are observed in
simulations and experiments. Our findings of nondispersive surface and hinge
states may promote applications in acoustic sensing and energy harvesting.
Resistance of a Josephson junction array consisting of randomly distributed
lead (Pb) islands on exfoliated single layer graphene shows a broad
superconducting transition to zero with an onset temperature close to the
transition temperature of bulk Pb. The transition evolves with the back-gate
voltage and exhibits two peaks in temperature derivative of resistance. The
region above the lower temperature peak is found to be well described by
Berezinskii-Kosterlitz-Thouless model of thermal unbinding of vortex
anti-vortex pairs while that below this peak fits well with the Ambegaokar-
Halperin model of thermally-activated phase slip or vortex motion in Josephson
junction arrays. Thus a gate-tunable crossover between interaction and pinning
dominated vortices is inferred as the Josephson energy, dictating the pinning
potential magnitude, increases with cooling while the effective screening
length, dictating the range of inter-vortex interaction, reduces.
We theoretically study the conditions under which a spin Nernst effect - a
transverse spin current induced by an applied temperature gradient - can occur
in a canted antiferromagnetic insulator, such as ${\rm LaFeO_3}$ and other
materials of the same family. The spin Nernst effect may provide a microscopic
mechanism for an experimentally observed anomalous thermovoltage in ${\rm
LaFeO_3}$/Pt heterostructures, where spin is transferred across the
insulator/metal interface when a temperature gradient is applied to ${\rm
LaFeO_3}$ parallel to the interface [W. Lin ${\it et \; al}$, Nat. Phys. ${\bf
18}$, 800 (2022)]. We find that ${\rm LaFeO_3}$ exhibits a topological spin
Nernst effect when inversion symmetry is broken on the axes parallel to both
the applied temperature gradient and the direction of spin transport, which can
result in a spin injection across the insulator/metal interface. Our work
provides a general derivation of a symmetry-breaking-induced spin Nernst
effect, which may open a path to engineering a finite spin Nernst effect in
systems where it would otherwise not arise.
Dark excitons in transition metal dichalcogenides (TMD) have been so far
neglected in the context of polariton physics due to their lack of oscillator
strength. However, in tungsten-based TMDs, dark excitons are known to be the
energetically lowest states and could thus provide important scattering
partners for polaritons. In this joint theory-experiment work, we investigate
the impact of the full exciton energy landscape on polariton absorption and
reflectance. By changing the cavity detuning, we vary the polariton energy
relative to the unaffected dark excitons in such a way that we open or close
specific phonon-driven scattering channels. We demonstrate both in theory and
experiment that this controlled switching of scattering channels manifests in
characteristic sharp changes in optical spectra of polaritons. These spectral
features can be exploited to extract the position of dark excitons. Our work
suggests new possibilities for exploiting polaritons for fingerprinting
nanomaterials via their unique exciton landscape.
We consider an effective Hubbard model with spin- and direction-dependent
complex hoppings $t$, applied to twisted homobilayer WSe$_2$ using a
variational Monte Carlo approach. The electronic correlations are taken into
account by applying the Gutzwiller on-site correlator as well as long-range
Jastrow correlators subjected to noninteracting part being of Pfaffian form.
Our analysis shows the emergence of Mott insulating state at critical value of
Hubbard interaction $U_{c1}\approx 6.5|t|\div7|t|$ estimated by extrapolating
the density-density equal-time two-particle Green's functions. The signatures
of an intermediate insulating phase between $U_{c1}$ and
$U_{c2}\approx9.5|t|\div10|t|$ are also discussed. Furthermore, we report the
formation of the $120^{\circ}$ in-plane N\'eel state indicated by the detailed
analysis of the spin-spin correlation functions. As shown, switching between
antiferromagnetic phases characterized by opposite chirality could be
experimentally realized by the change of perpendicular electric field. In
proper range of electric fields also a transition to in-plane ferromagnetic
state appears.
Hybrid multiferroic films are fabricated by depositing of Pt/Co/Pt
multilayers onto [001] and [110] cuts of PMN-PT crystal. The dependence of the
interfacial Dzyaloshinskii-Moriya interaction (iDMI) on applied electric field
is experimentally investigated in the system by the Brilloin light scattering
method. A strong variation (from -0.2 to 0.8 mJ/m2) of the iDMI constant is
observed when the electric field is applied. In the case of [001] cut, the
observed changes in the iDMI have an isotropic character, while in the case of
[110] cut they are anisotropic, which corresponds to the symmetry of the PMN-PT
deformations. The change in the iDMI is accompanied by the formation of various
unusual domain structures and skyrmion lattices. External control of the DMI
with an electric field opens the way to manipulate topological magnetic
solitons (such as skyrmions), which are promising objects for information
processing and storage.
Thin films of the pyrochlore iridates along the [111] direction have drawn
significant attention to investigate exotic correlated topological phenomena.
Here, we report the fabrication of Eu$_2$Ir$_2$O$_7$ thin films via reactive
solid phase epitaxy using the pulsed laser deposition technique. We mainly
focus on the transport properties of the films below the magnetic phase
transition at 105 K. Analyses on the temperature and the field dependences of
resistivity unveil the presence of weak antilocalization, a characteristic
signature of the Weyl semimetallic state that has been "buried" by magnetism.
Moreover, it is noteworthy that the contribution from many-body interactions in
Eu2Ir2O7 thin films is enhanced at lower temperatures and competes with the
weak antilocalization effect, and eventually drives the crossover to weak
localization at 2 K.
Weyl semimetals in three dimensions can exist independently of any symmetry
apart from translations. Conversely, in two dimensions, Weyl semimetals are
believed to require additional symmetries including crystalline symmetries to
exist. In this study, we demonstrate that a 2D Weyl semimetal phase can exist
in systems with Hamiltonians possessing internal symmetries, such as time
reversal ${\cal T}$, charge conjugation ${\cal C}$ , and their combined chiral
symmetry ${\cal S} = {\cal CT}$, only. Starting from a minimal-dimension Dirac
Hamiltonian, we establish the presence of a stable Weyl semimetal phase in each
of the five chiral classes: AIII, BDI, CII, DIII, and CI in two dimension.
Similar to 3D Weyl semimetals where Weyl points possess nontrivial topological
charges (Chern number), the Weyl points in WSMs within the 2D chiral classes
are characterized by the $Z$ winding numbers. In accordance with the
bulk-boundary correspondence, protected Fermi arc edge states emerge,
connecting the projections of Weyl points that carry opposite topological
charges. Unlike the surface states in 3D WSMs, the edge states of WSMs within
2D chiral classes are completely dispersionless and are always at the zero
energy due to the protecting chiral symmetry.
Based on the earlier published theory (Nature Mat. 18, 223-228 (2019)), a
comprehensive experimental investigation of multiferroic quantum critical
behavior of (Eu,Ba,Sr)TiO$_3$ polycrystalline and single crystal samples was
performed. Presence of the displacive ferroelectric quantum criticality is
revealed through non-classical ($T^2$) temperature scaling of inverse
dielectric susceptibility up to 60 K. With increasing hydrostatic pressure,
this ferroelectric quantum criticality is gradually suppressed. Inverse
magnetic susceptibility follows classical Curie-Weiss law down to 4 K, but
quantum fluctuations belonging to an antiferromagnetic phase transition
($T_{\mathrm{N}}$ < 0.8 K) change its scaling below 4 K to $T^{1.7}$ and
$T^{2.0}$ for samples containing 29 % and 25 % of Eu$^{2+}$ ions, respectively.
Observation of the coexisting ferroelectric and antiferromagnetic, i.e.
multiferroic, quantum fluctuations and qualitative explanation why they are
seen only in the immediate proximity of $T_{\mathrm{N}}$ is given.
We theoretically investigate a voltage-biased normal
metal-superconductor-normal metal (N-S-N) junction. Using the nonequilibrium
Green's function technique, we derive a quantum kinetic equation, to determine
the superconducting order parameter self-consistently. The derived equation is
an integral-differential equation with memory effects. We solve this equation
by converting it into a system of ordinary differential equations with the use
of a pole expansion of the Fermi-Dirac function. When the applied voltage
exceeds the critical value, the superconductor switches to the normal state. We
find that when the voltage is decreased from the normal phase, the system
relaxes to a Larkin-Ovchinnikov (LO)-type inhomogeneous superconducting state,
even in the absence of a magnetic Zeeman field. We point out that the emergence
of the LO-type state can be attributed to the nonequilibrium energy
distribution of electrons due to the bias voltage. We also point out that the
system exhibits bistability, which leads to hysteresis in the voltage-current
characteristic of the N-S-N junction.
Kagome lattices have garnered substantial interest because their band
structure consists of topological flat bands and Dirac cones. The RMn$_6$Sn$_6$
(R = rare earth) compounds are particularly interesting because of the
existence of large intrinsic anomalous Hall effect (AHE) which originates from
the gapped Dirac cones near the Fermi level. This makes RMn$_6$Sn$_6$ an
outstanding candidate for realizing the high-temperature quantum anomalous Hall
effect. The growth of RMn$_6$Sn$_6$ thin films is beneficial for both
fundamental research and potential applications. However, most of the studies
on RMn$_6$Sn$_6$ have focused on bulk crystals so far, and the synthesis of
RMn$_6$Sn$_6$ thin films has not been reported so far. Here we report the
atomic layer molecular beam epitaxy growth, structural and magnetic
characterizations, and transport properties of ErMn$_6$Sn$_6$ and
TbMn$_6$Sn$_6$ thin films. It is especially noteworthy that TbMn$_6$Sn$_6$ thin
films have out-of-plane magnetic anisotropy, which is important for realizing
the quantum anomalous Hall effect. Our work paves the avenue toward the control
of the AHE using devices patterned from RMn$_6$Sn$_6$ thin films.
Graphene nanoribbons are a promising candidate for fault-tolerant quantum
electronics. In this scenario, qubits are realised by localised states that can
emerge on junctions in hybrid ribbons formed by two armchair nanoribbons of
different widths. We derive an effective theory based on a tight-binding ansatz
for the description of hybrid nanoribbons and use it to make accurate
predictions of the energy gap and nature of the localisation in various hybrid
nanoribbon geometries. We discover, in addition to the well known localisations
on junctions, which we call `Fuji', a new type of `Kilimanjaro' localisation
smeared out over a segment of the hybrid ribbon. We show that Fuji
localisations in hybrids of width $N$ and $N+2$ armchair nanoribbons occur
around symmetric junctions if and only if $N\pmod3=1$, while edge-aligned
junctions never support strong localisation. This behaviour cannot be explained
relying purely on the topological $Z_2$ invariant, which has been believed the
origin of the localisations to date.
How multiple observables mutually influence their dynamics has been a crucial
issue in statistical mechanics. We introduce a new concept, "quantum velocity
limits," to establish a quantitative and rigorous theory for non-equilibrium
quantum dynamics for multiple observables. Quantum velocity limits are
universal inequalities for a vector the describes velocities of multiple
observables. They elucidate that the speed of an observable of our interest can
be tighter bounded when we have knowledge of other observables, such as
experimentally accessible ones or conserved quantities, compared with the
conventional speed limits for a single observable. We first derive an
information-theoretical velocity limit in terms of the generalized correlation
matrix of the observables and the quantum Fisher information. The velocity
limit has various novel consequences: (i) conservation law in the system, a
fundamental ingredient of quantum dynamics, can improve the velocity limits
through the correlation between the observables and conserved quantities; (ii)
speed of an observable can be bounded by a nontrivial lower bound from the
information on another observable; (iii) there exists a notable non-equilibrium
tradeoff relation, stating that speeds of uncorrelated observables, e.g.,
anti-commuting observables, cannot be simultaneously large; (iv) velocity
limits for any observables on a local subsystem in locally interacting
many-body systems remain convergent even in the thermodynamic limit. Moreover,
we discover another distinct velocity limit for multiple observables on the
basis of the local conservation law of probability current, which becomes
advantageous for macroscopic transitions of multiple quantities.
There is a version of the Landau-Lifshitz equation that takes into account
the Coulomb exchange interactions between atoms, expressed by the term
$\sim\bm{s}\times\triangle\bm{s}$. On the other hand, magnetic atoms and ions
have several valence electrons on the d-shell, and therefore the Hamiltonian of
many-electron atoms with spins S>1 should include a biquadratic exchange
interaction in the equation of magnetization (spin density) evolution. We first
propose a new fundamental microscopic derivation of such an equation with an
explicit form of biquadratic exchange interactions using the method of
many-particle quantum hydrodynamics. Although we are considering a crystal
lattice in which ions do not move, the resulting equations turn out to be
hydrodynamic. The equations for the evolution of the spin density are obtained
from the many-particle Schrodinger-Pauli equation and contain the contributions
of the usual Coulomb exchange interactions and, first, the biquadratic
exchange. Furthermore, the derived biquadratic exchamge torque in the spin
density evolution equation contains the nematic tensor for the medium of atoms
with spin $\textit{S=1}$. Our method may be very attractive for further studies
of the magnetoelectric effect in multiferroics with exchange interactions.
The formation of a heavy Fermi liquid in metals with local moments is
characterized by multiple energy and temperature scales, most prominently the
Kondo temperature and the coherence temperature, characterizing the onset of
Kondo screening and the emergence of Fermi-liquid coherence, respectively. In
the standard setting of a wide conduction band, both scales depend
exponentially on the Kondo coupling. Here we discuss how the presence of flat,
i.e., dispersionless, conduction bands modifies this situation. Focussing on
the case of the kagome Kondo-lattice model, we utilize a parton mean-field
approach to determine the Kondo temperature and the coherence temperature as
function of the conduction-band filling $n_c$, both numerically and
analytically. For $n_c$ values corresponding to the flat conduction band
located at the Fermi level, we show that the exponential is replaced by a
linear dependence for the Kondo temperature and a quadratic dependence for the
coherence temperature, while a cubic law emerges for the coherence temperature
at $n_c$ corresponding to the band edge between the flat and dispersive bands.
We discuss implications of our results for pertinent experimental data.
In this paper we explore the properties of a 1-dimensional spin chain in the
presence of chiral interactions, focusing on the system's transition to
distinct chiral phases for various values of the chiral coupling. By employing
the mean field theory approximation we establish a connection between this
chiral system and a Dirac particle in the curved spacetime of a black hole.
Surprisingly, the black hole horizon coincides with the interface between
distinct chiral phases. We examine the chiral properties of the system for
homogeneous couplings and in scenarios involving position dependent couplings
that correspond to black hole geometries. To determine the significance of
interactions in the chiral chain we employ bosonization techniques and derive
the corresponding Luttinger liquid model. Furthermore, we investigate the
classical version of the model to understand the impact of the chiral operator
on the spins and gain insight into the observed chirality. Our findings shed
light on the behavior of the spin chain under the influence of the chiral
operator, elucidating the implications of chirality in various contexts,
including black hole physics.
We computed the phase diagram of the zigzag graphene nanoribbons as a
function of on-site repulsion, doping, and disorder strength. The topologically
ordered phase undergoes topological phase transitions into crossover phases,
which are new disordered phases with a nonuniversal topological entanglement
entropy with significant variance. The topological order is destroyed by
competition between localization effects and on-site repulsion. We found that
strong on-site repulsion and/or doping weakens the nonlocal correlations
between the opposite zigzag edges. In one of the crossover phases, both
$\frac{e^-}{2}$ fractional charges and spin-charge separation were absent;
however, charge-transfer correlations between the zigzag edges were possible.
Another crossover phase contains $\frac{e^-}{2}$ fractional charges, but no
charge transfer correlations. In low-doped zigzag ribbons the interplay between
electron localization and on-site repulsion contributes to the spatial
separation of quasi-degenerate gap-edge states and protects the charge
fractionalization against quantum fluctuations. In all these effects, mixed
chiral gap-edge states play an important role. The properties of nontopological
strongly disordered and strongly repulsive phases are also observed. Each phase
of the phase diagram has a different zigzag-edge structure.
Hexagonal boron nitride exhibits two types of defects with great potential
for quantum information technologies: single-photon emitters (SPEs) and
one-dimensional grain boundaries hosting topologically-protected phonons,
termed as {\it{topologically-protected phonon lines}} (TPL). Here, by means of
a simple effective model and density functional theory calculations, we show
that it is possible to use these phonons for the transmission of information.
Particularly, a single SPE can be used to induce single-, two- and qubit-phonon
states in the one dimensional channel, and \textit{(ii)} two distant SPEs can
be coupled by the TPL that acts as a waveguide, thus exhibiting strong quantum
correlations. We highlight the possibilities offered by this material-built-in
nano-architecture as a phononic device for quantum information technologies.
The quasi-one-dimensional chiral compound (TaSe$_4$)$_2$I has been
extensively studied as a prime example of a topological Weyl semimetal. Upon
crossing its phase transition temperature $T_\textrm{CDW}$ $\approx$ 263 K,
(TaSe$_4$)$_2$I exhibits incommensurate charge density wave (CDW) modulations
described by the well-defined propagation vector $\sim$(0.05, 0.05, 0.11),
oblique to the TaSe$_4$ chains. Although optical and transport properties
greatly depend on chirality, there is no systematic report about chiral domain
size for (TaSe$_4$)$_2$I. In this study, our single-crystal scattering
refinements reveal a bulk iodine deficiency, and Flack parameter measurements
on multiple crystals demonstrate that separate (TaSe$_4$)$_2$I crystals have
uniform handedness, supported by direct imaging and helicity dependent THz
emission spectroscopy. Our single-crystal X-ray scattering and calculated
diffraction patterns identify multiple diffuse features and create a real-space
picture of the temperature-dependent (TaSe$_4$)$_2$I crystal structure. The
short-range diffuse features are present at room temperature and decrease in
intensity as the CDW modulation develops. These transverse displacements, along
with electron pinning from the iodine deficiency, help explain why
(TaSe$_4$)$_2$I behaves as an electronic semiconductor at temperatures above
and below $T_\textrm{CDW}$, despite a metallic band structure calculated from
density functional theory of the ideal structure.
We study the low-energy eigenstates of a topological superconductor wire
modeled by a Kitaev chain, which is connected at one of its ends to a quantum
dot through nearest-neighbor (NN) hopping and NN Coulomb repulsion. Using an
unrestricted Hartree-Fock approximation to decouple the Coulomb term, we obtain
that the quality of the Majorana end states is seriously affected by this term
only when the dependence of the low-lying energies with the energy of the
quantum dot shows a "diamond" shape, characteristic of short wires. We discuss
limitations of the simplest effective models to describe the physics. We expect
the same behavior in more realistic models for topological superconducting
wires.
Chimera states are dynamical states where regions of synchronous trajectories
coexist with incoherent ones. A significant amount of research has been devoted
to study chimera states in systems of identical oscillators, non-locally
coupled through pairwise interactions. Nevertheless, there is an increasing
evidence, also supported by available data, that complex systems are composed
by multiple units experiencing many-body interactions, that can be modeled by
using higher-order structures beyond the paradigm of classic pairwise networks.
In this work we investigate whether phase chimera states appear in this
framework, by focusing on a novel topology solely involving many-body,
non-local and non-regular interactions, hereby named non-local d-hyperring,
being (d+1) the order of the interactions. We present the theory by using the
paradigmatic Stuart-Landau oscillators as node dynamics, and show that phase
chimera states emerge in a variety of structures and with different coupling
functions. For comparison, we show that, when higher-order interactions are
"flattened" to pairwise ones, the chimera behavior is weaker and more elusive.
We show that many-body fermionic non-Hermitian systems require two distinct
sets of topological invariants to describe the topology of energy bands and
quantum states respectively, with the latter yet to be explored. We identify 10
symmetry classes -- determined by particle-hole, linearized time-reversal, and
linearized chiral symmetries. Each class has topological invariant associated
with each dimension, dictating the topology of quantum states. These findings
pave the way for deeper understanding of the topological phases of many-body
non-Hermitian systems.
We propose an effective model for the study of the interplay between
correlation and topology by decorating the Kane-Mele model with a set of
localized interacting orbitals hybridized to just one sublattice, breaking the
inversion symmetry. We show that in the time-reversal symmetric case, the
interplay between interactions and hybridization extends the stability of the
topological phase and depending on the driving mechanism very different
behaviors are observed after the topological phase transition (TPT). We discuss
the fate of the TPT in presence of weak ferromagnetic order, by introducing a
weak local magnetic field at the localized orbitals, which splits the two band
inversion points. One of the platforms to apply this model to are ferrovalley
compounds, which are characterized by two independent band inversion points.
Understanding this family of materials is crucial for the development of the
valleytronics. An alternative to spintronics, which uses valley polarization as
opposed to spin degrees of freedom as the building block, promises great
opportunities for the development of information storage.
The time evolution of topological systems is an active area of interest due
to their expected applications in fault-tolerant quantum computing. Here, we
analyze the dynamics of a non-interacting spinless fermion chain in its
topological phase, quenched out-of-equilibrium by a Hamiltonian belonging to
the same symmetry class. Due to particle-hole symmetry, the bulk properties of
the system remain intact throughout its evolution. However, the boundary
properties may be drastically altered, with the initially localized Majorana
edge modes extending across the chain. Up to a timescale $t^*$, identified by
area-law behavior of the entanglement entropy, these extended edge modes are an
example of exotic effects in topological systems out-of-equilibrium. Further,
whilst local disorder can be utilized to preserve localization and increase
$t^*$, we still identify non-trivial dynamics in the Majorana polarization and
Loschmidt echo.
We study the coupling of two topologcal subsystems in distinct topological
states, and show that it leads to a precursor behavior of the topological phase
transition in the overall system. This behavior is solely determined by the
symmetry classes of the subsystem Hamiltonians and coupling terms, and is
marked by the persistent existence of subgap states within the bulk energy gap.
By investigating the critical current of Josephson junctions involving
topological superconductors, we also illustrate that such subgap states play
crucial roles in physical properties of nanoscale devices or materials.
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.
Integer or fractional quantum Hall crystals, states postulating the
coexistence of charge order with integer or fractional quantum Hall effect,
have long been proposed in theoretical studies in Landau levels. Inspired by
recent experiments on integer or fractional quantum anomalous Hall (IQAH/FQAH)
states in MoTe2 and rhombohedral multilayer graphene, this work examines the
archetypal correlated flat band model on a checkerboard lattice at filling
{\nu} = 2/3. Interestingly, at this filling level, we find that this
topological flatband does not stabilize conventional FQAH states. Instead, the
unique interplay between smectic charge order and topological order gives rise
to two intriguing quantum states. As the interaction strength increases, the
system first transitions from a Fermi liquid into FQAH smectic (FQAHS) states,
where FQAH topological order coexists cooperatively with smectic charge order.
With a further increase in interaction strength, the system undergoes another
quantum phase transition and evolves into a polar smectic metal. Contrary to
conventional smectic order and FQAHS states, this gapless state spontaneously
breaks the two-fold rotational symmetry, resulting in a nonzero electric dipole
moment and ferroelectric order. In addition to identifying the ground states,
large-scale numerical simulations are also used to study low-energy excitations
and thermodynamic characteristics. We find that FQAHS states exhibit two
distinct temperature scales: the onset of charge order and the onset of the
fractional Hall plateau, respectively. Interestingly, the latter is dictated by
charge-neutral low-energy excitations with finite momenta, known as
magnetorotons. Our studies suggest that these nontrivial phenomena could, in
principle, be accessed in future experiments with moir\'e systems.

Date of feed: Wed, 10 Jan 2024 01:30:00 GMT**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **"Quantum Geometric Nesting'' and Solvable Model Flat-Band Systems. (arXiv:2401.04163v1 [cond-mat.str-el])**

Zhaoyu Han, Jonah Herzog-Arbeitman, B. Andrei Bernevig, Steven A. Kivelson

**The Odd Fermion. (arXiv:2401.04223v1 [hep-th])**

Daniel S. Freed, Michael J. Hopkins, Constantin Teleman

**Electron quantum optics in graphene. (arXiv:2401.04233v1 [cond-mat.mes-hall])**

Himadri Chakraborti, Cosimo Gorini, Angelika Knothe, Ming-Hao Liu, Péter Makk, Francois D. Parmentier, David Perconte, Klaus Richter, Preden Roulleau, Benjamin Sacépé, Christian Schönenberger, Wenmin Yang

**Shear deformation in CuZr metallic glass: A statistical and complex network analysis. (arXiv:2401.04252v1 [cond-mat.mtrl-sci])**

Fernando Corvacho, Victor Muñoz, Matias Sepulveda-Macias, Gonzalo Gutierrez

**Flexible thermoelectrics in crossed graphene/hBN composites. (arXiv:2401.04274v1 [cond-mat.mtrl-sci])**

M.Amir Bazrafshan, Farhad Khoeini

**Revisiting the Landau criterion: a hydrodynamic and holographic approach to superfluid instabilities. (arXiv:2401.04275v1 [hep-th])**

Filippo Sottovia

**New twisted van der Waals fabrication method based on strongly adhesive polymer. (arXiv:2401.04313v1 [cond-mat.mtrl-sci])**

Giung Park, Suhan Son, Jongchan Kim, Yunyeong Chang, Kaixuan Zhang, Miyoung Kim, Jieun Lee, Je-Geun Park

**Gate-tunable topological phases in superlattice modulated bilayer graphene. (arXiv:2401.04321v1 [cond-mat.mes-hall])**

Yongxin Zeng, Tobias M. R. Wolf, Chunli Huang, Nemin Wei, Sayed Ali Akbar Ghorashi, Allan H. MacDonald, Jennifer Cano

**Long-lived topological time-crystalline order on a quantum processor. (arXiv:2401.04333v1 [quant-ph])**

Liang Xiang, Wenjie Jiang, Zehang Bao, Zixuan Song, Shibo Xu, Ke Wang, Jiachen Chen, Feitong Jin, Xuhao Zhu, Zitian Zhu, Fanhao Shen, Ning Wang, Chuanyu Zhang, Yaozu Wu, Yiren Zou, Jiarun Zhong, Zhengyi Cui, Aosai Zhang, Ziqi Tan, Tingting Li, Yu Gao, Jinfeng Deng, Xu Zhang, Hang Dong, Pengfei Zhang, Si Jiang, Weikang Li, Zhide Lu, Zheng-Zhi Sun, Hekang Li, Zhen Wang, Chao Song, Qiujiang Guo, Fangli Liu, Zhe-Xuan Gong, Alexey V. Gorshkov, Norman Y. Yao, Thomas Iadecola, Francisco Machado, H. Wang, Dong-Ling Deng

**Kibble-Zurek scalings and coarsening laws in slowly quenched classical Ising chains. (arXiv:2401.04342v1 [cond-mat.stat-mech])**

Lakshita Jindal, Kavita Jain

**Controlling chaos: Periodic defect braiding in active nematics confined to a cardioid. (arXiv:2401.04363v1 [cond-mat.soft])**

Fereshteh L. Memarian, Derek Hammar, Md Mainul Hasan Sabbir, Mark Elias, Kevin A. Mitchell, Linda Hirst

**Characterization of two fast-turnaround dry dilution refrigerators for scanning probe microscopy. (arXiv:2401.04373v1 [cond-mat.mes-hall])**

Mark E. Barber, Yifan Li, Jared Gibson, Jiachen Yu, Zhanzhi Jiang, Yuwen Hu, Zhurun Ji, Nabhanila Nandi, Jesse C. Hoke, Logan Bishop-Van Horn, Gilbert R. Arias, Dale J. Van Harlingen, Kathryn A. Moler, Zhi-Xun Shen, Angela Kou, Benjamin E. Feldman

**Spin current leakage and Onsager reciprocity in interfacial spin-charge interconversion. (arXiv:2401.04413v1 [cond-mat.mes-hall])**

Aurelien Manchon, Shuyuan Shi, Hyunsoo Yang

**Band Geometry Induced High-Angular Momentum Excitonic Superfluid in Gapped Chiral Fermion Systems. (arXiv:2401.04416v1 [cond-mat.mes-hall])**

Huaiyuan Yang, Yuelin Shao, Xi Dai, Xin-Zheng Li

**Disorder-induced topological superconductivity in a spherical quantum-Hall--superconductor hybrid. (arXiv:2401.04426v1 [cond-mat.mes-hall])**

Koji Kudo, Ryota Nakai, Kentaro Nomura

**Electrodynamics of superconductors: from Lorentz to Galilei at zero temperature. (arXiv:2401.04493v1 [cond-mat.supr-con])**

Luca Salasnich

**Observation of Higher Order Nodal Line Semimetal in Phononic Crystals. (arXiv:2401.04502v1 [cond-mat.mes-hall])**

Qiyun Ma, Zhenhang Pu, Liping Ye, Jiuyang Lu, Xueqin Huang, Manzhu Ke, Hailong He, Weiyin Deng, Zhengyou Liu

**Gate-tunable crossover between vortex-interaction and pinning dominated regimes in Josephson-coupled Lead-islands on graphene. (arXiv:2401.04532v1 [cond-mat.supr-con])**

Suraina Gupta, Santu Prasad Jana, Rukshana Pervin, Anjan K. Gupta

**Topological transverse spin transport in a canted antiferromagnet/heavy metal heterostructure. (arXiv:2401.04582v1 [cond-mat.mes-hall])**

Wesley Roberts, Bowen Ma, Martin Rodriguez-Vega, Gregory A. Fiete

**Revealing dark exciton signatures in polariton spectra of 2D materials. (arXiv:2401.04588v1 [cond-mat.mes-hall])**

Beatriz Ferreira, Hangyong Shan, Roberto Rosati, Jamie M. Fitzgerald, Lukas Lackner, Bo Han, Martin Esmann, Patrick Hays, Gilbert Liebling, Kenji Watanabe, Takashi Taniguchi, Falk Eilenberger, Sefaattin Tongay, Christian Schneider, Ermin Malic

**Variational Monte-Carlo Approach for Hubbard Model Applied to Twisted Bilayer WSe$_2$ at Half-Filling. (arXiv:2401.04593v1 [cond-mat.str-el])**

Andrzej Biborski, Paweł Wójcik, Michał Zegrodnik

**Electric field manipulation of the Dzyaloshinskii-Moriya interacion in hybrid multiferroic structures. (arXiv:2401.04615v1 [cond-mat.mtrl-sci])**

O.G. Udalov, R.V. Gorev, N.S. Gusev, A.V. Sadovnikov, M.V. Sapozhnikov

**Weak antilocalization and localization in Eu$_2$Ir$_2$O$_7$ (111) thin films by reactive solid phase epitaxy. (arXiv:2401.04644v1 [cond-mat.str-el])**

Xiaofeng Wu, Zhen Wang, Zhaoqing Ding, Zeguo Lin, Mingyu Yang, Minghui Gu, Meng Meng, Fang Yang, Xiaoran Liu, Jiandong Guo

**Protected Weyl semimetals within 2D chiral classes. (arXiv:2401.04656v1 [cond-mat.mes-hall])**

Faruk Abdulla

**Multiferroic quantum criticality in (Eu,Ba,Sr)TiO$_3$ solid solution. (arXiv:2401.04677v1 [cond-mat.mtrl-sci])**

Dalibor Repček, Petr Proschek, Maxim Savinov, Martin Kachlík, Jiří Pospíšil, Jan Drahokoupil, Petr Doležal, Jan Prokleška, Stanislav Kamba

**Emergence of Larkin-Ovchinnikov-type superconducting state in a voltage-driven superconductor. (arXiv:2401.04684v1 [cond-mat.supr-con])**

Taira Kawamura, Yoji Ohashi, H.T.C. Stoof

**Atomic Layer Molecular Beam Epitaxy of Kagome Magnet RMn$_6$Sn$_6$ (R = Er, Tb) Thin Films. (arXiv:2401.04713v1 [cond-mat.mtrl-sci])**

Shuyu Cheng, Igor Lyalin, Wenyi Zhou, Roland K. Kawakami

**An Effective Theory for Graphene Nanoribbons with Junctions. (arXiv:2401.04715v1 [cond-mat.mes-hall])**

Johann Ostmeyer, Lado Razmadze, Evan Berkowitz, Thomas Luu, Ulf-G. Meißner

**Quantum Velocity Limits for Multiple Observables: Conservation Laws, Correlations, and Macroscopic Systems. (arXiv:2305.03190v4 [cond-mat.stat-mech] UPDATED)**

Ryusuke Hamazaki

**A new microscopic representation of the spin dynamics in quantum systems with the Coulomb exchange interactions. (arXiv:2305.03826v2 [cond-mat.mtrl-sci] UPDATED)**

Mariya Iv. Trukhanova, Pavel Andreev

**Kondo screening and coherence in kagome local-moment metals: Energy scales of heavy fermions in the presence of flat bands. (arXiv:2305.16198v2 [cond-mat.str-el] UPDATED)**

Christos Kourris, Matthias Vojta

**Exploring interacting chiral spin chains in terms of black hole physics. (arXiv:2305.19169v2 [cond-mat.str-el] UPDATED)**

Ewan Forbes, Matthew D. Horner, Andrew Hallam, Joseph Barker, Jiannis K. Pachos

**Phase Diagram and Crossover Phases of Topologically Ordered Graphene Zigzag Nanoribbons: Role of Localization Effects. (arXiv:2307.04352v2 [cond-mat.str-el] UPDATED)**

Hoang Anh Le, In Hwan Lee, Young Heon Kim, S.-R. Eric Yang

**Generation of phonon quantum states and quantum correlations among single photon emitters in hexagonal boron nitride. (arXiv:2308.06244v2 [quant-ph] UPDATED)**

Hugo Molinares, Fernanda Pinilla, Enrique Muñoz, Francisco Muñoz, Vitalie Eremeev

**Disorder and diffuse scattering in single-chirality (TaSe$_4$)$_2$I crystals. (arXiv:2309.10236v3 [cond-mat.str-el] UPDATED)**

Jacob A. Christensen, Simon Bettler, Kejian Qu, Jeffrey Huang, Soyeun Kim, Yinchuan Lu, Chengxi Zhao, Jin Chen, Matthew J. Krogstad, Toby J. Woods, Fahad Mahmood, Pinshane Y. Huang, Peter Abbamonte, Daniel P. Shoemaker

**Effect of interatomic repulsion on Majorana zero modes in a coupled quantum-dot-superconducting-nanowire hybrid system. (arXiv:2309.10888v2 [cond-mat.mes-hall] UPDATED)**

R. Kenyi Takagui Perez, A. A. Aligia

**Phase chimera states on non-local hyperrings. (arXiv:2310.15540v2 [nlin.PS] UPDATED)**

Riccardo Muolo, Thierry Njougouo, Lucia Valentina Gambuzza, Timoteo Carletti, Mattia Frasca

**Topological phases of many-body non-Hermitian systems. (arXiv:2311.03043v2 [quant-ph] UPDATED)**

Kui Cao, Su-Peng Kou

**Impact of correlations on topology in Kane-Mele model decorated with impurities. (arXiv:2311.07379v2 [cond-mat.str-el] UPDATED)**

Jan Skolimowski, Wojciech Brzezicki, Carmine Autieri

**Extended edge modes and disorder preservation of a symmetry-protected topological phase out-of-equilibrium. (arXiv:2311.09610v2 [cond-mat.str-el] UPDATED)**

Thomas L. M. Lane, Miklós Horváth, Kristian Patrick

**Precursors to Topological Phase Transition in Topological Ladders. (arXiv:2311.11673v2 [cond-mat.mes-hall] UPDATED)**

Seungju Han, Mahn-Soo Choi

**Chiral symmetry breaking and topological charge of graphene nanoribbons. (arXiv:2312.05487v2 [cond-mat.mes-hall] UPDATED)**

Hyun Cheol Lee, S.-R. Eric Yang

**From Fractional Quantum Anomalous Hall Smectics to Polar Smectic Metals: Nontrivial Interplay Between Electronic Liquid Crystal Order and Topological Order in Correlated Topological Flat Bands. (arXiv:2401.00363v2 [cond-mat.str-el] UPDATED)**

Hongyu Lu, Han-Qing Wu, Bin-Bin Chen, Kai Sun, Zi Yang Meng

Found 6 papers in prb This work investigates the zero-temperature physics of generalized Bose-Hubbard models, which conserve finite Fourier momenta of the particle number. Analytical and numerical calculations predict a novel quasi-long-range order phase, in addition to more conventional Mott insulators. The former is characterized by a two-species Luttinger liquid in the infrared, with microscopic expectation values dressed by oscillatory contributions. The authors also conjecture that this phase is destroyed by the unbinding of topological defects along the temporal direction even when they are confined along the transverse direction. Recent experiments indicate that crystalline graphene multilayers exhibit much of the richness of their twisted counterparts, including cascades of symmetry-broken states and unconventional superconductivity. Interfacing Bernal bilayer graphene with a ${\mathrm{WSe}}_{2}$ monolayer was shown to dram… We use the Lindblad equation approach to investigate topological phases hosting more than one localized state at each side of a disordered Su-Schrieffer-Heeger chain with properly tuned long-range hoppings. Inducing a nonequilibrium steady state across the chain, we probe the robustness of each phas… The recent discovery of superconductivity in magic-angle twisted trilayer graphene (MATTG) has sparked significant interest. Here we focus on MATTG, where the low energy flat bands and linearly dispersive Dirac bands coexist and can be decoupled by external fields. Using a continuum model, we examin… The electric field gradient (EFG) and magnetic excitation of TaSb${}_{2}$ were studied using nuclear quadrupole resonance (NQR) in a single crystal. The EFG parameters determined by measuring all expected NQR lines were corroborated by density functional theory (DFT) calculations. Despite the good agreement between the measured and calculated Sommerfeld coefficients, the spin-lattice relaxation rate was not captured by the DFT band calculations. To overcome this discrepancy, the authors propose a site-dependent in-gap state with an average energy gap of ~7 meV for the Sb sites and ~22 meV for the Ta site, which are much smaller than the semimetallic gap. While magnetic fields generally compete with superconductivity, a type II superconductor can persist to very high fields by confining the field within the topological defects, namely the vortices. We propose that a similar physics underlies the pseudogap phase in the cuprates, where the relevant top…

Date of feed: Wed, 10 Jan 2024 04:17:02 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) **Exotic quantum liquids in Bose-Hubbard models with spatially modulated symmetries**

Pablo Sala, Yizhi You, Johannes Hauschild, and Olexei Motrunich

Author(s): Pablo Sala, Yizhi You, Johannes Hauschild, and Olexei Motrunich

[Phys. Rev. B 109, 014406] Published Tue Jan 09, 2024

**Correlated phases in spin-orbit-coupled rhombohedral trilayer graphene**

Jin Ming Koh, Jason Alicea, and Étienne Lantagne-Hurtubise

Author(s): Jin Ming Koh, Jason Alicea, and Étienne Lantagne-Hurtubise

[Phys. Rev. B 109, 035113] Published Tue Jan 09, 2024

**Fate of high winding number topological phases in the disordered extended Su-Schrieffer-Heeger model**

Emmanuele G. Cinnirella, Andrea Nava, Gabriele Campagnano, and Domenico Giuliano

Author(s): Emmanuele G. Cinnirella, Andrea Nava, Gabriele Campagnano, and Domenico Giuliano

[Phys. Rev. B 109, 035114] Published Tue Jan 09, 2024

**Robust and reentrant superconductivity in magic-angle twisted trilayer graphene**

Jie Cao, Fenghua Qi, Yuanyuan Xiang, and Guojun Jin

Author(s): Jie Cao, Fenghua Qi, Yuanyuan Xiang, and Guojun Jin

[Phys. Rev. B 109, 035115] Published Tue Jan 09, 2024

**Experimental nuclear quadrupole resonance and computational study of the structurally refined topological semimetal ${\mathrm{TaSb}}_{2}$**

T. Fujii, O. Janson, H. Yasuoka, H. Rosner, Yu. Prots, U. Burkhardt, M. Schmidt, and M. Baenitz

Author(s): T. Fujii, O. Janson, H. Yasuoka, H. Rosner, Yu. Prots, U. Burkhardt, M. Schmidt, and M. Baenitz

[Phys. Rev. B 109, 035116] Published Tue Jan 09, 2024

**Theory of cuprate pseudogap as antiferromagnetic order with charged domain walls**

R. S. Markiewicz and A. Bansil

Author(s): R. S. Markiewicz and A. Bansil

[Phys. Rev. B 109, 045116] Published Tue Jan 09, 2024

Found 1 papers in prl

Date of feed: Wed, 10 Jan 2024 04:17:00 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) **Comment on “Anomalous Reentrant $5/2$ Quantum Hall Phase at Moderate Landau-Level-Mixing Strength”**

Steven H. Simon

Author(s): Steven H. Simon

[Phys. Rev. Lett. 132, 029601] Published Tue Jan 09, 2024