Found 27 papers in cond-mat The grand canonical ensemble of a $d$-dimensional Reissner-Nordstr\"om black
hole space in a cavity is analyzed. The realization of this ensemble is made
through the Euclidean path integral approach by giving the Euclidean action for
the black hole with the correct topology, and boundary conditions corresponding
to a cavity, where the fixed quantities are the temperature and the electric
potential. One performs a zero loop approximation to find and analyze the
stationary points of the reduced action. This yields two solutions for the
electrically charged black hole, $r_{+1}$, which is the smaller and unstable,
and $r_{+2}$, which is the larger and stable. One also analyzes the most
probable configurations, which are either a stable charged black hole or hot
flat space, mimicked by a nongravitating charged shell. Making the
correspondence between the action and the grand potential, one can get the
black hole thermodynamic quantities, such as the entropy, the mean charge, the
mean energy, and the thermodynamic pressure, as well as the Smarr formula,
shown to be valid only for the unstable black hole. We find that thermodynamic
stability is related to the positivity of the heat capacity at constant
electric potential and area of the cavity. We also comment on the most
favorable thermodynamic phases and phase transitions. We then choose $d = 5$,
which is singled out naturally from the other higher dimensions as it provides
an exact solution for the problem, and apply all the results previously found.
The case $d = 4$ is mentioned. We compare thermodynamic radii with the photonic
orbit radius and the Buchdahl-Andr\'easson-Wright bound radius in
$d$-dimensional Reissner-Nordstr\"om spacetimes and find they are unconnected,
showing that the connections displayed in the Schwarzschild case are not
generic, rather they are very restricted holding only in the pure gravitational
situation.
While free fermion topological crystalline insulators have been largely
classified, the analogous problem in the strongly interacting case has been
only partially solved. In this paper, we develop a characterization and
classification of interacting, invertible fermionic topological phases in (2+1)
dimensions with charge conservation, discrete magnetic translation and $M$-fold
point group rotation symmetries, which form the group $G_f = \text{U}(1)^f
\times_{\phi} [\mathbb{Z}^2\rtimes \mathbb{Z}_M]$ for $M=1,2,3,4,6$. $\phi$ is
the magnetic flux per unit cell. We derive a topological response theory in
terms of background crystalline gauge fields, which gives a complete
classification of different phases and a physical characterization in terms of
quantized response to symmetry defects. We then derive the same classification
in terms of a set of real space invariants $\{\Theta_{\text{o}}^\pm\}$ that can
be obtained from ground state expectation values of suitable partial rotation
operators. We explicitly relate these real space invariants to the quantized
coefficients in the topological response theory, and find the dependence of the
invariants on the chiral central charge $c_-$ of the invertible phase. Finally,
when $\phi = 0$ we derive an explicit map between the free and interacting
classifications.
The equilibrium phase space of magnetic textures in thin-films of cubic
chiral ferromagnets, including skyrmions, is explored as a function of in-plane
magnetic field strength, film thickness and uniaxial anisotropy. The interplay
between these system parameters is found to give rise to a phase space with a
rich structure, distinct from that of the nano-stripes that have been
previously studied. For certain values of the anisotropy, the range of
thicknesses supporting in-plane skyrmions and/or helicoids with an out-of-plane
propagation vector is found to be disconnected, suggesting a possible direction
for future experiments. We explain how this interesting phase space topology
arises due to the geometric confinement of the thin-film system, and identify
the optimal parameter ranges for future explorations of novel magnetic textures
such as the oblique spiral phase.
CaSb$_2$ has been identified as a bulk superconductor and a topological
semimetal, which makes it a great platform for realizing topological
superconductivity. In this work, we investigate the superconducting upper and
lower critical field anisotropy using magnetic susceptibility, and study the
superconducting state using muon spin-relaxation. The temperature dependence of
transverse-field relaxation can be fitted with a single-gap model or two-gap
model, consistent with previous tunnel-diode oscillator measurements. We
highlight that the normal state of CaSb$_2$ shows a large diamagnetic signal,
which is likely related to its Dirac semimetal nature. Zero-field relaxation
shows little temperature dependence when the muon-spin is parallel to the
$c*$-axis, while an increase in relaxation appears below 1~K when the muon-spin
is parallel to the $ab$-plane. This may be related to a second superconducting
phase appearing at low temperature below the bulk $T_c$ . However, we find no
discernible anomaly in $\mu_{\rm{0}} H_{\rm{c1}}(0)$ around this temperature as
has been seen in other superconductors with secondary superconducting states
that appear at lower temperatures.
The quantum nature of electron spin is crucial for establishing topological
invariants in real materials. Since the spin does not in general commute with
the Hamiltonian, some of the topological features of the material can be
extracted from its study. In insulating materials, the spin operator induces a
projected operator on valence states called the spin valence operator. Its
spectrum contains information with regard to the different phases of the spin
Chern class. If the spin valence spectrum is gapped, the spin Chern numbers are
constant along parallel planes thus defining spin Chern insulating materials.
If the spin valence spectrum is not gapped, the changes in the spin Chern
numbers occur whenever this spectrum is zero. Materials whose spin valence
spectrum are gapless will be denoted spin Weyl topological insulators and its
definition together with some of their properties will be presented in this
work. The classification of materials from the properties of the spin valence
operator provides a new characterization which complements the existing list of
topological invariants.
In this manuscript, we show through an experimental-computational proof of
concept the native oxide formation into superconducting TaN films. First, TaN
was synthesized at an ultra-high vacuum system by reactive pulsed laser
deposition and characterized in situ by X-ray photoelectron spectroscopy. The
material was also characterized ex situ by X-ray diffraction, transmission
electron microscopy, and the four-point probe method. It was detected that TaN
contained considerable oxygen impurities (up to 26 %O) even though it was grown
in an ultra-high vacuum chamber. Furthermore, the impurified TaN evidence a
face-centered cubic crystalline structure only and exhibits superconductivity
at 2.99 K. To understand the feasibility of the native oxide in TaN, we study
the effect of incorporating different amounts of O atoms in TaN using ab-initio
calculations. A thermodynamic stability analysis shows that a TaOxN1-x model
increases its stability as oxygen is added, demonstrating that oxygen may
always be present in TaN, even when obtained at ultra-high vacuum conditions.
All analyzed models exhibit metallic behavior. Charge density difference maps
reveal that N and O atoms have a higher charge density redistribution than Ta
atoms. The electron localization function maps and line profiles indicate that
Ta-O and Ta-N bonds are mainly ionic. As expected, stronger ionic behavior is
observed in the Ta-O bonds due to the electronegativity difference between O
and N atoms. Recent evidence points to superconductivity in bulk TaO,
confirming the asseverations of superconductivity in our samples. The results
discussed here highlight the importance of considering native oxide when
reporting superconductivity in TaN films since the TaO regions formed in the
compound may be key to understanding the different critical temperatures
reported in the literature.
In quantum computing, characterising the full noise profile of qubits can aid
the efforts towards increasing coherence times and fidelities by creating error
mitigating techniques specific to the type of noise in the system, or by
completely removing the sources of noise. Spin qubits in MOS quantum dots are
exposed to noise originated from the complex glassy behaviour of two-level
fluctuators, leading to non-trivial correlations between qubit properties both
in space and time. With recent engineering progress, large amounts of data are
being collected in typical spin qubit device experiments, and it is beneficiary
to explore data analysis options inspired from fields of research that are
experienced in managing large data sets, examples include astrophysics, finance
and climate science. Here, we propose and demonstrate wavelet-based analysis
techniques to decompose signals into both frequency and time components to gain
a deeper insight into the sources of noise in our systems. We apply the
analysis to a long feedback experiment performed on a state-of-the-art
two-qubit system in a pair of SiMOS quantum dots. The observed correlations
serve to identify common microscopic causes of noise, as well as to elucidate
pathways for multi-qubit operation with a more scalable feedback system.
Droplet coalescence is a common phenomenon and plays an important role in
multi-disciplinary applications. Previous studies mainly consider the
coalescence of miscible liquid, even though the coalescence of immiscible
droplets on a solid surface is a common process. In this study, we explore the
coalescence of two immiscible droplets on a partial wetting surface
experimentally and theoretically. We find that the coalescence process can be
divided into three stages based on the timescales and force interactions
involved, namely (I) the growth of the liquid bridge, (II) the oscillation of
the coalescing sessile droplet, and (III) the formation of a partially-engulfed
compound sessile droplet and the subsequent retraction. In stage I, the
immiscible interface is found not to affect the scaling of the temporal
evolution of the liquid bridge, which follows the same 2/3 power law as that of
miscible droplets. In Stage II, by developing a new capillary timescale
considering both surface and interfacial tensions, we show that the interfacial
tension between the two immiscible liquids functions as a nonnegligible
resistance to the oscillation which decreases the oscillation periods. In Stage
III, a modified Ohnesorge number is developed to characterize the
visco-capillary and inertia-capillary timescales involved during the
displacement of water by oil; a new model based on energy balance is proposed
to analyze the maximum retraction velocity, highlighting that the viscous
resistance is concentrated in a region close to the contact line.
We investigate the effects of the curved geometry on a massless relativistic
electron constrained to a graphene strip with a Moebius strip shape. The
anisotropic and parity-violating geometry of the Moebius band produces a
geometric potential that inherits these features. By considering wires along
the strip width and the strip length, we find exact solutions for the Dirac
equation and the effects of the geometric potential on the electron were
explored. In both cases, the geometric potential yields to a geometric phase on
the wave function. Along the strip width, the density of states depends on the
direction chosen for the wire, a consequence of the lack of axial symmetry.
Moreover, the breaking of the parity symmetry enables the electronic states to
be concentrated on the inner or on the outer portion of the strip. For wires
along the strip length, the nontrivial topology influences the eigenfunctions
by modifying their periodicity. It turns out that the ground state has a period
of $4\pi$ whereas the first excited state is a $2\pi$ periodic function.
Moreover, we found that the energy levels are half-integer multiples of the
energy of the ground state.
We present a temperature- and polarization-resolved phononic and electronic
Raman scattering study in combination with the first-principles calculations on
the kagome metal Ni$_3$In with anisotropic transport properties and non-Fermi
liquid behavior. At temperatures below 50 K and down to 2 K, several Raman
phonon modes, including particularly an interlayer shear mode, exhibit
appreciable frequency and linewidth renormalization, reminiscent of the onset
of the Kondo screening without an accompanying structural or magnetic phase
transition. In addition, a low-energy electronic continuum observed in
polarization perpendicular to the kagome planes reveals strong temperature
dependence below 50 K, implying thermal depletion of incoherent quasiparticles,
while the in-plane continuum remains invariant. These concomitant electronic
and phononic Raman signatures suggest that Ni$_3$In undergoes an anisotropic
electronic crossover from an incoherent to a coherent Kondo lattice regime
below 50 K. We discuss the origin of the anisotropic incoherent-coherent
crossover in association with the possible anisotropic Kondo hybridization
involving localized Ni-$3d_{xz}$ flat-band electrons.
Frustrated magnetic systems can host highly interesting phases known as
classical spin liquids (CSLs), which feature {extensive} ground state
degeneracy and lack long-range magnetic order. Recently, Yan and Benton et al.
proposed a classification scheme of CSLs in the large-$\mathcal{N}$ (soft spin)
limit [arXiv.2305.00155, arXiv:2305.19189]. This scheme classifies CSLs into
two categories: the algebraic CSLs and the fragile topological CSLs, each with
their own correlation properties, low energy effective description, and finer
classification frameworks. In this work, we further develop the classification
scheme by considering the role of crystalline symmetry. We present a
mathematical framework for computing the band representation of the flat bands
in the spectrum of these CSLs, which extends beyond the conventional
representation analysis. It allows one to determine whether the algebraic CSLs,
which features gapless points on their bottom flat bands, are protected by
symmetry or not. It also provides more information on the finer classifications
of algebraic and fragile topological CSLs. We demonstrate this framework via
concrete examples and showcase its power by constructing a pinch-line algebraic
CSL protected by symmetry.
Ferroelectricity in the complementary metal-oxide semiconductor
(CMOS)-compatible hafnia (HfO$_2$) is crucial for the fabrication of
high-integration nonvolatile memory devices. However, the capture of
ferroelectricity in HfO$_2$ requires the stabilization of
thermodynamically-metastable orthorhombic or rhombohedral phases, which entails
the introduction of defects (e.g., dopants and vacancies) and pays the price of
crystal imperfections, causing unpleasant wake-up and fatigue effects. Here, we
report a theoretical strategy on the realization of robust ferroelectricity in
HfO$_2$-based ferroelectrics by designing a series of epitaxial
(HfO$_2$)$_1$/(CeO$_2$)$_1$ superlattices. The advantages of the designated
ferroelectric superlattices are defects free, and most importantly, on the base
of the thermodynamically stable monoclinic phase of HfO$_2$. Consequently, this
allows the creation of superior ferroelectric properties with an electric
polarization $>$25 $\mu$C/cm$^2$ and an ultralow polarization-switching energy
barrier at $\sim$2.5 meV/atom. Our work may open an entirely new route towards
the fabrication of high-performance HfO$_2$ based ferroelectric devices.
An important class of model Hamiltonians for investigation of topological
phases of matter consists of mobile, interacting particles on a lattice subject
to a semi-classical gauge field, as exemplified by the bosonic
Harper-Hofstadter model. A unique method for investigations of two-dimensional
quantum systems are the infinite projected-entangled pair states (iPEPS), as
they avoid spurious finite size effects that can alter the phase structure.
However, due to no-go theorems in related cases this was often conjectured to
be impossible in the past. In this letter, we show that upon variational
optimization the infinite projected-entangled pair states can be used to this
end, by identifying fractional Hall states in the bosonic Harper-Hofstadter
model. The obtained states are characterized by showing exponential decay of
bulk correlations, as dictated by a bulk gap, as well as chiral edge modes via
the entanglement spectrum.
Photocurrent matching in conventional monolithic tandem solar cells is
achieved by choosing semiconductors with complementary absorption spectra and
by carefully adjusting the optical properties of the complete top and bottom
stacks. However, for thin film photovoltaic technologies at the module level,
another design variable significantly alleviates the task of photocurrent
matching, namely the cell width, whose modification can be readily realized by
the adjustment of the module layout. Herein we demonstrate this concept at the
experimental level for the first time for a 2T-mechanically stacked perovskite
(FAPbBr3)/organic (PM6:Y6:PCBM) tandem mini-module, an unprecedented approach
for these emergent photovoltaic technologies fabricated in an independent
manner. An excellent Isc matching is achieved by tuning the cell widths of the
perovskite and organic modules to 7.22 mm (PCEPVKT-mod= 6.69%) and 3.19 mm
(PCEOPV-mod= 12.46%), respectively, leading to a champion efficiency of 14.94%
for the tandem module interconnected in series with an aperture area of 20.25
cm2. Rather than demonstrating high efficiencies at the level of small lab
cells, our successful experimental proof-of-concept at the module level proves
to be particularly useful to couple devices with non-complementary
semiconductors, either in series or in parallel electrical connection, hence
overcoming the limitations imposed by the monolithic structure.
We propose an experimental scheme to realize non-Abelian dynamical gauge
field for ultracold fermions, which induces a novel pairing mechanism of
topological superfluidity. The dynamical gauge fields arise from nontrivial
interplay effect between the strong Zeeman splitting and Hubbard interaction in
a two-dimensional (2D) optical Raman lattice. The spin-flip transitions are
forbidden by the large Zeeman detuning, but are restored when the Zeeman
splitting is compensated by Hubbard interaction. This scheme allows to generate
a dynamical non-Abelian gauge field that leads to a Dirac type correlated 2D
spin-orbit interaction depending on local state configurations. The topological
superfluid from a novel pairing driven by 2D dynamical gauge fields is reached,
with analytic and numerical results being obtained. Our work may open up a door
to emulate non-Abelian dynamical gauge fields and correlated topological phases
with experimental feasibility.
Femtosecond laser excitation of materials that exhibit magnetic spin textures
promises advanced magnetic control via the generation of ultrafast and
non-equilibrium spin dynamics. We explore such possibilities in ferrimagnetic
[Fe(0.35 nm)/Gd(0.40 nm)]$_{160}$ multilayers, which host a rich diversity of
magnetic textures from stripe domains at low magnetic fields, a dense
bubble/skyrmion lattice at intermediate fields, and a single domain state for
high magnetic fields. Using femtosecond magneto-optics, we observe distinct
coherent spin wave dynamics in response to a weak laser excitation allowing us
to unambiguously identify the different magnetic spin textures. Moreover,
employing strong laser excitation we show that we achieve versatile control of
the coherent spin dynamics via non-equilibrium and ultrafast transformation of
magnetic spin textures by both creating and annihilating bubbles/skyrmions. We
corroborate our findings by micromagnetic simulations and by Lorentz
transmission electron microscopy before and after laser exposure.
Despite the recent successes of vanilla Graph Neural Networks (GNNs) on many
tasks, their foundation on pairwise interaction networks inherently limits
their capacity to discern latent higher-order interactions in complex systems.
To bridge this capability gap, we propose a novel approach exploiting the rich
mathematical theory of simplicial complexes (SCs) - a robust tool for modeling
higher-order interactions. Current SC-based GNNs are burdened by high
complexity and rigidity, and quantifying higher-order interaction strengths
remains challenging. Innovatively, we present a higher-order Flower-Petals (FP)
model, incorporating FP Laplacians into SCs. Further, we introduce a
Higher-order Graph Convolutional Network (HiGCN) grounded in FP Laplacians,
capable of discerning intrinsic features across varying topological scales. By
employing learnable graph filters, a parameter group within each FP Laplacian
domain, we can identify diverse patterns where the filters' weights serve as a
quantifiable measure of higher-order interaction strengths. The theoretical
underpinnings of HiGCN's advanced expressiveness are rigorously demonstrated.
Additionally, our empirical investigations reveal that the proposed model
accomplishes state-of-the-art (SOTA) performance on a range of graph tasks and
provides a scalable and flexible solution to explore higher-order interactions
in graphs.
Active matter systems, from self-propelled colloids to motile bacteria, are
characterized by the conversion of free energy into useful work at the
microscopic scale. These systems generically involve physics beyond the reach
of equilibrium statistical mechanics, and a persistent challenge has been to
understand the nature of their nonequilibrium states. The entropy production
rate and the magnitude of the steady-state probability current provide
quantitative ways to do so by measuring the breakdown of time-reversal symmetry
and the strength of nonequilibrium transport of measure. Yet, their efficient
computation has remained elusive, as they depend on the system's unknown and
high-dimensional probability density. Here, building upon recent advances in
generative modeling, we develop a deep learning framework that estimates the
score of this density. We show that the score, together with the microscopic
equations of motion, gives direct access to the entropy production rate, the
probability current, and their decomposition into local contributions from
individual particles, spatial regions, and degrees of freedom. To represent the
score, we introduce a novel, spatially-local transformer-based network
architecture that learns high-order interactions between particles while
respecting their underlying permutation symmetry. We demonstrate the broad
utility and scalability of the method by applying it to several
high-dimensional systems of interacting active particles undergoing
motility-induced phase separation (MIPS). We show that a single instance of our
network trained on a system of 4096 particles at one packing fraction can
generalize to other regions of the phase diagram, including systems with as
many as 32768 particles. We use this observation to quantify the spatial
structure of the departure from equilibrium in MIPS as a function of the number
of particles and the packing fraction.
Detecting Majorana fermions in experimental realizations of the Kitaev
honeycomb model is often complicated by non-trivial interactions inherent to
potential spin liquid candidates. In this work, we identify several distinct
thermodynamic signatures of massive, itinerant Majorana fermions within the
well-established analytical paradigm of Landau-Fermi liquid theory. We find a
qualitative and quantitative agreement between the salient features of our
Landau-Majorana liquid theory and the Kitaev spin liquid candidate
Ag$_3$LiIr$_2$O$_6$. Our study presents strong evidence for a Fermi liquid-like
ground state in the fundamental excitations of a honeycomb iridate, and opens
new experimental avenues to detect itinerant Majorana fermions in condensed
matter systems.
We study two-dimensional (2D) droplets of noninteracting electrons in a
strong magnetic field, placed in a confining potential with arbitrary shape.
Using semiclassical methods adapted to the lowest Landau level, we obtain
near-Gaussian energy eigenstates that are localized on level curves of the
potential and have a position-dependent height. This one-particle insight
allows us to deduce explicit formulas for expectation values of local many-body
observables, such as density and current, in the thermodynamic limit. In
particular, correlations along the edge are long-ranged and inhomogeneous. As
we show, this is consistent with the system's universal low-energy description
as a free 1D chiral conformal field theory of edge modes, known from earlier
works in simple geometries. A delicate interplay between radial and angular
dependencies of eigenfunctions ultimately ensures that the theory is
homogeneous in terms of the canonical angle variable of the potential, despite
its apparent inhomogeneity in terms of more na\"ive angular coordinates.
Finally, we propose a scheme to measure the anisotropy by subjecting the
droplet to microwave radiation; we compute the corresponding absorption rate
and show that it depends on the droplet's shape and the waves' polarization.
These results, both local and global, are likely to be observable in
solid-state systems or quantum simulators of 2D electron gases with a high
degree of control on the confining potential.
The recently discovered vanadium-based Kagome metals $A$V$_{3}$Sb$_{5}$ ($A =
\text{K, Rb, Cs}$) are of great interest with the interplay of charge density
wave (CDW) order, band topology and superconductivity. In this paper, by
identifying elementary band representations (EBRs), we construct a two-EBR
graphene-Kagome model to capture the two low-energy van-Hove-singularity
dispersions and, more importantly, the nontrivial band topology in these Kagome
metals. This model consists of $A_g@3g$ (V-$d_{x^2-y^2/z^2}$, Kagome sites) and
$A_2''@2d$ EBRs (Sb1-$p_z$, honeycomb sites). We have investigated the Fermi
surface instability by calculating the electronic susceptibility
$\chi(\mathbf{q})$. Prominent Fermi-surface nesting peaks are obtained at three
L points, where the $z$ component of the nesting vector shows intimate
relationship with the anticrossing point along M--L. The nesting peaks at L are
consistent with the $2\times 2\times 2$ CDW reconstruction in these compounds.
In addition, the sublattice-resolved bare susceptibility is calculated and
similar sharp peaks are observed at the L points, indicating a strong
antiferromagnetic fluctuation. Assuming a bulk $s$-wave superconducting
pairing, helical surface states and nontrivial superconducting gap are obtained
on the (001) surface. In analogous to FeTe$_{1-x}$Se$_{x}$ superconductor, our
results establish another material realization of a stoichiometric
superconductor with nontrivial band topology, providing a promising platform
for studying exotic Majorana physics in condensed matter
Type-II Dirac semimetals (DSMs) have a distinct Fermi surface topology, which
allows them to host novel topological superconductivity (TSC) different from
type-I DSMs. Depending on the relationship between intra- and inter-orbital
electron-electron interactions, the phase diagram of superconductivity is
obtained in type-II DSMs. We find that when the inter-orbital attraction is
dominant, an unconventional inter-orbital intra-spin superconducting (SC) state
($B_{1u}$ and $B_{2u}$ pairing channels of $D_{4h}$ point group) is realized,
yielding hybrid TSC, i.e., first- and second-order TSC exists at the same time.
Further analysis reveals the Majorana flat bands on the $z$-directed hinges,
which penetrate through the whole hinge Brillouin zone and link the projections
of the surface helical Majorana cones at time-reversal-invariant momenta. These
higher-order hinge modes are symmetry-protected and can even host strong
stability against finite $C_{4z}$ rotation symmetry-breaking order. We suggest
that experimental realization of these findings can be explored in transition
metal dichalcogenides.
Architected materials possessing physico-chemical properties adaptable to
disparate environmental conditions embody a disruptive new domain of materials
science. Fueled by advances in digital design and fabrication, materials shaped
into lattice topologies enable a degree of property customization not afforded
to bulk materials. A promising venue for inspiration toward their design is in
the irregular micro-architectures of nature. However, the immense design
variability unlocked by such irregularity is challenging to probe analytically.
Here, we propose a new computational approach using graph-based representation
for regular and irregular lattice materials. Our method uses differentiable
message passing algorithms to calculate mechanical properties, therefore
allowing automatic differentiation with surrogate derivatives to adjust both
geometric structure and local attributes of individual lattice elements to
achieve inversely designed materials with desired properties. We further
introduce a graph neural network surrogate model for structural analysis at
scale. The methodology is generalizable to any system representable as
heterogeneous graphs.
We use numerical simulations and linear stability analysis to study the
dynamics of an active liquid crystal film on a substrate in the regime where
the passive system would be isotropic. Extensile activity builds up local
orientational order and destabilizes the quiescent isotropic state above a
critical activity value, eventually resulting in spatiotemporal chaotic
dynamics akin to the one observed ubiquitously in the nematic state. Here we
show that tuning substrate friction yields a variety of emergent structures at
intermediate activity, including lattices of flow vortices with associated
regular arrangements of topological defects and a new state where flow vortices
trap pairs of $+1/2$ defect that chase each other tail. These chiral units
spontaneously pick the sense of rotation and organize in a hexagonal lattice,
surrounded by a diffuse flow of opposite rotation to maintain zero net
vorticity. The length scale of these emergent structures is set by the
screening length $l_\eta=\sqrt{\eta/\Gamma}$ of the flow, controlled by the
shear viscosity $\eta$ and the substrate friction $\Gamma$, and can be captured
by simple mode selection of the vortical flows. We demonstrate that the
emergence of coherent structures can be interpreted as a phase separation of
vorticity, where friction plays a role akin to that of birth/death processes in
breaking conservation of the phase separating species and selecting a
characteristic scale for the patterns. Our work shows that friction provides an
experimentally accessible tuning parameter for designing controlled active
flows.
Strong interactions between charges and light-matter coupled quasiparticles
offer an intriguing prospect with applications from optoelectronics to
light-induced superconductivity. Here, we investigate how the interactions
between electrons and exciton-polaritons in a two-dimensional semiconductor
microcavity can be resonantly enhanced due to a strong coupling to a trion,
i.e., an electron-exciton bound state. We develop a microscopic theory that
uses a strongly screened interaction between charges to enable the summation of
all possible diagrams in the polariton-electron scattering process. The
position and magnitude of the resonance is found to vary depending on the
values of the light-matter coupling and detuning, thus indicating a large
degree of tunability. We furthermore derive an analytic approximation of the
interaction strength based on universal lowenergy scattering theory. This is
found to match extremely well with our full calculation, indicating that the
trion resonance is near universal, depending more on the strength of the
light-matter coupling relative to the trion binding energy rather than on the
details of the electronic interactions. Thus, we expect the trion resonance in
polariton-electron scattering to appear in a broad range of microcavity systems
with few semiconductor layers, such as doped monolayer MoSe2 where such
resonances have recently been observed experimentally [Sidler et al., Nature
Physics 13, 255 (2017)].
We provide sufficient conditions such that the time evolution of a mesoscopic
tight-binding open system with a local Hartree-Fock non-linearity converges to
a self-consistent non-equilibrium steady state, which is independent of the
initial condition from the "small sample". We also show that the steady charge
current intensities are given by Landauer-B\"uttiker-like formulas, and make
the connection with the case of weakly self-interacting many-body systems.
The combination of a superconductor (SC) and a topological insulator (TI)
nanowire was proposed as a potential candidate for realizing Majorana zero
modes (MZMs). In this study, we adopt the Schr\"odinger-Poisson formalism to
incorporate the electrostatic environment inside the nanowire and
systematically explore its topological properties. Our calculations reveal that
the proximity to the SC induces a band bending effect, leading to a non-uniform
potential across the TI nanowire. As a consequence, there is an upward shift of
the Fermi level within the conduction band. This gives rise to the coexistence
of surface and bulk states, localized in an accumulation layer adjacent to the
TI-SC interface. When magnetic flux is applied, these occupied states have
different flux-penetration areas, suppressing the superconducting gap. However,
this impact can be mitigated by increasing the radius of the nanowire. Finally,
We demonstrate that MZMs can be achieved across a wide range of parameters
centered around one applied flux quantum, $\phi_0 = h/2e$. Within this regime,
MZMs can be realized even in the presence of conduction bands, which are not
affected by the band bending effect. These findings provide valuable insights
into the practical realization of MZMs in TI nanowire-based devices, especially
in the presence of a complicated electrostatic environment.

Date of feed: Mon, 25 Sep 2023 00:30:00 GMT**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **Grand canonical ensemble of a $d$-dimensional Reissner-Nordstr\"om black hole in a cavity. (arXiv:2309.12388v1 [hep-th])**

Tiago V. Fernandes, José P. S. Lemos

**Characterization and classification of interacting (2+1)D topological crystalline insulators with orientation-preserving wallpaper groups. (arXiv:2309.12389v1 [cond-mat.str-el])**

Naren Manjunath, Vladimir Calvera, Maissam Barkeshli

**The influence of film thickness and uniaxial anisotropy on in-plane skyrmions: Numerical investigations of the phase space of chiral magnets. (arXiv:2309.12419v1 [cond-mat.mtrl-sci])**

Cameron Rudderham, Martin Plumer, Theodore Monchesky

**Critical Field Anisotropy and Muon Spin Relaxation Study of Superconducting Dirac-Semimetal CaSb$_2$. (arXiv:2309.12457v1 [cond-mat.supr-con])**

M. Oudah, Y. Cai, M. V. De Toro Sanchez, J. Bannies, M. C. Aronson, K. M. Kojima, D. A. Bonn

**Spin Weyl Topological Insulators. (arXiv:2309.12470v1 [cond-mat.mtrl-sci])**

Rafael Gonzalez-Hernandez, Bernardo Uribe

**Experimental and theoretical assessment of native oxide in the superconducting TaN. (arXiv:2309.12520v1 [cond-mat.supr-con])**

V. Quintanar-Zamora, M. Cedillo-Rosillo, O. Contreras-López, C. Corona-García, A. Reyes-Serrato, R. Ponce-Pérez, J. Guerrero-Sánchez, J. A. Díaz

**Spatio-temporal correlations of noise in MOS spin qubits. (arXiv:2309.12542v1 [quant-ph])**

Amanda E. Seedhouse, Nard Dumoulin Stuyck, Santiago Serrano, Tuomo Tanttu, Will Gilbert, Jonathan Yue Huang, Fay E. Hudson, Kohei M. Itoh, Arne Laucht, Wee Han Lim, Chih Hwan Yang, Andrew S. Dzurak, Andre Saraiva

**Coalescence of immiscible sessile droplets on a partial wetting surface. (arXiv:2309.12561v1 [physics.flu-dyn])**

Huadan Xu, Xinjin Ge, Tianyou Wang, Zhizhao Che

**Dirac fermions on wires confined to the graphene Moebius strip. (arXiv:2309.12609v1 [cond-mat.mes-hall])**

L. N. Monteiro, J. E. G. Silva, C. A. S. Almeida

**Fingerprints for anisotropic Kondo lattice behavior in the quasiparticle dynamics of the kagome metal Ni$_3$In. (arXiv:2309.12648v1 [cond-mat.str-el])**

Dong-Hyeon Gim, Dirk Wulferding, Chulwan Lee, Hengbo Cui, Kiwan Nam, Myung Joon Han, Kee Hoon Kim

**Classification of Classical Spin Liquids: Topological Quantum Chemistry and Crystalline Symmetry. (arXiv:2309.12652v1 [cond-mat.str-el])**

Yuan Fang, Jennifer Cano, Andriy H. Nevidomskyy, Han Yan

**Engineering ferroelectricity in monoclinic hafnia. (arXiv:2309.12800v1 [cond-mat.mtrl-sci])**

Hong Jian Zhao, Yuhao Fu, Longju Yu, Yanchao Wang, Yurong Yang, Laurent Bellaiche, Yanming Ma

**Fractional quantum Hall states with variational Projected Entangled-Pair States: a study of the bosonic Harper-Hofstadter model. (arXiv:2309.12811v1 [cond-mat.str-el])**

Erik Lennart Weerda, Matteo Rizzi

**Matching the photocurrent of perovskite/organic tandem solar modules by varying the cell width. (arXiv:2309.12890v1 [cond-mat.mtrl-sci])**

Jose Garcia Cerrillo (1), Andreas Distler (1), Fabio Matteocci (2), Karen Forberich (3), Michael Wagner (3), Robin Basu (1), Luigi Angelo Castriotta (2), Farshad Jafarzadeh (2), Francesca Brunetti (2), Fu Yang (4), Ning Li (1, 3, and 5), Asiel Neftali Corpus Mendoza (6), Aldo Di Carlo (2 and 7), Christoph J. Brabec (1 and 3), Hans-Joachim Egelhaaf (1 and 3) ((1) Institute of Materials for Electronics and Energy Technology (i-MEET) of the Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), (2) Center for Hybrid and Organic Solar Energy (CHOSE) of the University of Rome Tor Vergata, (3) Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (HI-ERN), (4) Laboratory of Advanced Optoelectronic Materials of the Soochow University, (5) State Key Laboratory of Luminescent Materials and Devices of the South China University of Technology, (6) Instituto de Energias Renovables (IER) of the Universidad Nacional Autonoma de Mexico, (7) Institute of Structure of Matter (ISM) of the National Research Council (CNR))

**Non-Abelian dynamical gauge field and topological superfluids in optical Raman lattice. (arXiv:2309.12923v1 [cond-mat.quant-gas])**

Xin-Chi Zhou, Tian-Hua Yang, Zhi-Yuan Wang, Xiong-Jun Liu

**Laser-induced real-space topology control of spin wave resonances. (arXiv:2309.12956v1 [cond-mat.mtrl-sci])**

Tim Titze, Sabri Koraltan, Timo Schmidt, Marcel Möller, Florian Bruckner, Claas Abert, Dieter Suess, Claus Ropers, Daniel Steil, Manfred Albrecht, Stefan Mathias

**Higher-order Graph Convolutional Network with Flower-Petals Laplacians on Simplicial Complexes. (arXiv:2309.12971v1 [cs.LG])**

Yiming Huang, Yujie Zeng, Qiang Wu, Linyuan Lü

**Deep learning probability flows and entropy production rates in active matter. (arXiv:2309.12991v1 [cond-mat.stat-mech])**

Nicholas M. Boffi, Eric Vanden-Eijnden

**Signatures of a Majorana-Fermi surface in the Kitaev magnet Ag$_3$LiIr$_2$O$_6$. (arXiv:2108.03246v2 [cond-mat.str-el] UPDATED)**

Joshuah T. Heath, Faranak Bahrami, Sangyun Lee, Roman Movshovich, Xiao Chen, Fazel Tafti, Kevin S. Bedell

**Anisotropic Quantum Hall Droplets. (arXiv:2301.01726v3 [cond-mat.mes-hall] UPDATED)**

Blagoje Oblak, Bastien Lapierre, Per Moosavi, Jean-Marie Stéphan, Benoit Estienne

**Two elementary band representation model, Fermi surface nesting, and surface topological superconductivity in $A$V$_{3}$Sb$_ {5}$ ($A = \text{K, Rb, Cs}$). (arXiv:2302.06211v2 [cond-mat.mtrl-sci] UPDATED)**

Junze Deng, Ruihan Zhang, Yue Xie, Xianxin Wu, Zhijun Wang

**Hybrid Topological Superconductivity and Hinge Majorana Flat Band in Type-II Dirac Semimetals. (arXiv:2303.11729v2 [cond-mat.supr-con] UPDATED)**

Yue Xie, Xianxin Wu, Zhong Fang, Zhijun Wang

**Differentiable graph-structured models for inverse design of lattice materials. (arXiv:2304.05422v2 [cond-mat.mtrl-sci] UPDATED)**

Dominik Dold, Derek Aranguren van Egmond

**Vorticity phase separation and defect lattices in the isotropic phase of active liquid crystals. (arXiv:2306.04526v2 [cond-mat.soft] UPDATED)**

Fernando Caballero, Zhihong You, M. Cristina Marchetti

**Trion resonance in polariton-electron scattering. (arXiv:2307.08244v2 [cond-mat.mes-hall] UPDATED)**

Sangeet S. Kumar, Brendan C. Mulkerin, Meera M. Parish, Jesper Levinsen

**On the self-consistent Landauer-B\"uttiker formalism. (arXiv:2309.01564v2 [math-ph] UPDATED)**

Horia D. Cornean, Giovanna Marcelli

**Electrostatic environment and Majorana bound states in full-shell topological insulator nanowires. (arXiv:2309.11149v2 [cond-mat.mes-hall] UPDATED)**

Li Chen, Xiao-Hong Pan, Zhan Cao, Dong E. Liu, Xin Liu

Found 1 papers in sci-rep Scientific Reports, Published online: 24 September 2023; doi:10.1038/s41598-023-43269-6**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **X-ray dynamical diffraction by quasi-monolayer graphene**

Vyacheslav V. Lizunov