Found 59 papers in cond-mat We study a class of multi-orbital models based on those proposed by
Venderbos, Hu, and Kane which exhibit an interplay of topology, interactions,
and fermion incoherence. In the non-interacting limit, these models exhibit
trivial and Chern insulator phases with Chern number $C \geq 1$ bands as
determined by the relative angular momentum of the participating orbitals.
These quantum anomalous Hall insulator phases are separated by topological
transitions protected by crystalline rotation symmetry, featuring Dirac or
quadratic band-touching points. Here we study the impact of Sachdev-Ye-Kitaev
(SYK) type interactions on these lattice models. Given the random interactions,
these models display `average symmetries' upon disorder averaging, including a
charge conjugation symmetry, so they behave as interacting models in
topological class $\mathbf{D}$ enriched by crystalline rotation symmetry. The
phase diagram of this model features a non-Fermi liquid at high temperature and
an exciton condensate with nematic transport at low temperature. We present
results for the free-energy, spectral functions, and the anomalous Hall
resistivity as a function of temperature and tuning parameters. Our results are
broadly relevant to correlated topological matter in multiorbital systems, and
may also be viewed, with a suitable particle hole transformation, as an
exploration of strong interaction effects on mean-field topological
superconductors. \end{abstract}
Network science provides very powerful tools for extracting information from
interacting data. Although recently the unsupervised detection of phases of
matter using machine learning has raised significant interest, the full
prediction power of network science has not yet been systematically explored in
this context. Here we fill this gap by providing an in-depth statistical,
combinatorial, geometrical and topological characterization of 2D Ising
snapshot networks (IsingNets) extracted from Monte Carlo simulations of the 2D
Ising model at different temperatures, going across the phase transition. Our
analysis reveals the complex organization properties of IsingNets in both the
ferromagnetic and paramagnetic phases and demonstrates the significant
deviations of the IsingNets with respect to randomized null models. In
particular percolation properties of the IsingNets reflect the existence of the
symmetry between configurations with opposite magnetization below the critical
temperature and the very compact nature of the two emerging giant clusters
revealed by our persistent homology analysis of the IsingNets. Moreover, the
IsingNets display a very broad degree distribution and significant
degree-degree correlations and weight-degree correlations demonstrating that
they encode relevant information present in the configuration space of the 2D
Ising model. The geometrical organization of the critical IsingNets is
reflected in their spectral properties deviating from the one of the null
model. This work reveals the important insights that network science can bring
to the characterization of phases of matter. The set of tools described hereby
can be applied as well to numerical and experimental data.
Heterostructures of two-dimensional (2D) van der Waals (vdW) magnets and
topological insulators (TI) are of substantial interest as candidate materials
for efficient spin-torque switching, quantum anomalous Hall effect, and chiral
spin textures. However, since many of the vdW magnets have Curie temperatures
below room temperature, we want to understand how materials can be modified to
stabilize their magnetic ordering to higher temperatures. In this work, we
utilize molecular beam epitaxy to systematically tune the Curie temperature
($T_C$) in thin film Fe$_3$GeTe$_2$/Bi$_2$Te$_3$ from bulk-like values
($\sim$220 K) to above room temperature by increasing the growth temperature
from 300 $^\circ$C to 375 $^\circ$C. For samples grown at 375 $^\circ$C,
cross-sectional scanning transmission electron microscopy (STEM) reveals the
spontaneous formation of different Fe$_m$Ge$_n$Te$_2$ compositions (e.g.
Fe$_5$Ge$_2$Te$_2$ and Fe$_7$Ge$_6$Te$_2$) as well as intercalation in the vdW
gaps, which are possible origins of the enhanced Curie temperature. This
observation paves the way for developing various Fe$_m$Ge$_n$Te$_2$/TI
heterostructures with novel properties.
A new mechanism for memristive switching in 2D materials is through
electric-field controllable electronic/structural phase transitions, but these
devices have not outperformed status quo 2D memristors. Here, we report a
high-performance bipolar phase change memristor from strain engineered
multilayer 1T'-MoTe$_{2}$ that now surpasses the performance metrics (on/off
ratio, switching voltage, switching speed) of all 2D memristive devices,
achieved without forming steps. Using process-induced strain engineering, we
directly pattern stressed metallic contacts to induce a semimetallic to
semiconducting phase transition in MoTe2 forming a self-aligned vertical
transport memristor with semiconducting MoTe$_{2}$ as the active region. These
devices utilize strain to bring them closer to the phase transition boundary
and achieve ultra-low ~90 mV switching voltage, ultra-high ~10$^8$ on/off
ratio, 5 ns switching, and retention of over 10$^5$ s. Engineered tunability of
the device switching voltage and on/off ratio is also achieved by varying the
single process parameter of contact metal film force (film stress $\times$ film
thickness).
We establish a general Langevin Dynamics model of interacting, single-domain
magnetic nanoparticles in liquid suspension at finite temperature. The model
couples the LLG equation for the moment dynamics with the mechanical rotation
and translation of the particles. Within this model, we derive expressions for
the instantaneous transfer of energy, linear and angular momentum between the
particles and with the environment. We demonstrate by numerical tests that all
conserved quantities are fully accounted for, thus validating the model and the
transfer expressions. The energy transfer expressions derived here are also
useful analysis tools to decompose the instantaneous, non-equilibrium power
loss at each MNP into different loss channels. To demonstrate the model
capabilities, we analyse simulations of MNP collisions and high-frequency
hysteresis in terms of power and energy contributions.
Defects in graphene are both a boon and a bane for device application - they
can induce uncontrollable effects but can also provide novel ways to manipulate
the properties of pristine graphene. For this report, we investigated graphene
with no defect, one and two mono-vacancies, and two di-vancancies using a
Molecular Dynamics procedure optimized for the purpose. The defects that are
deemed to be energetically stable are identified and their formation mechanisms
proposed. We also investigated interaction between two Stone-Wales 55-77
defects, and the formation energies of their linearly extended structures,
along the zigzag and armchair direction, and when they are placed in different
relative orientations.
Magnetic chains on superconductors hosting Majorna Zero Modes (MZMs)
attracted high interest due to their possible applications in fault-tolerant
quantum computing. However, this is hindered by the lack of a detailed,
quantitative understanding of these systems. As a significant step forward, we
present a first-principles computational approach based on a microscopic
relativistic theory of inhomogeneous superconductors applied to an iron chain
on the top of Au-covered Nb(110) to study the Shiba band structure and the
topological nature of the edge states. Contrary to contemporary considerations,
our method enables the introduction of quantities indicating band inversion
without fitting parameters in realistic experimental settings, holding thus the
power to determine the topological nature of zero energy edge states in an
accurate ab-initio based description of the experimental systems. We confirm
that ferromagnetic Fe chains on Au/Nb(110) surface do not support any separated
MZM; however, a broad range of spin-spirals can be identified with robust zero
energy edge states displaying signatures of MZMs. For these spirals, we explore
the structure of the superconducting order parameter shedding light on the
internally antisymmetric triplet pairing hosted by MZMs. We also reveal a
two-fold effect of spin-orbit coupling: although it tends to enlarge the
topological phase regarding spin spiraling angles, however, it also extends the
localization of MZMs. Due to the presented predictive power, our work fills a
big gap between the experimental efforts and theoretical models while paving
the way for engineering platforms for topological quantum computation.
The interplay among symmetry of lattices, electronic correlations, and Berry
phase of the Bloch states in solids has led to fascinating quantum phases of
matter. A prototypical system is the magnetic Weyl candidate SrRuO3, where
designing and creating electronic and topological properties on artificial
lattice geometry is highly demanded yet remains elusive. Here, we establish an
emergent trigonal structure of SrRuO3 by means of heteroepitaxial strain
engineering along the [111] crystallographic axis. Distinctive from bulk, the
trigonal SrRuO3 exhibits a peculiar XY-type ferromagnetic ground state, with
the coexistence of high-mobility holes likely from linear Weyl bands and
low-mobility electrons from normal quadratic bands as carriers. The presence of
Weyl nodes are further corroborated by capturing intrinsic anomalous Hall
effect, acting as momentum-space sources of Berry curvatures. The experimental
observations are consistent with our first-principles calculations, shedding
light on the detailed band topology of trigonal SrRuO3 with multiple pairs of
Weyl nodes near the Fermi level. Our findings signify the essence of magnetism
and Berry phase manipulation via lattice design and pave the way towards
unveiling nontrivial correlated topological phenomena.
Recent advances in electron spin resonance techniques have allowed the
manipulation of the spin of individual atoms, making magnetic atomic chains on
superconducting hosts one of the most promising platform where topological
superconductivity can be engineered. Motivated by this progress, we provide a
detailed, quantitative description of the effects of manipulating spins in
realistic nanowires by applying a first-principles-based computational approach
to a recent experiment: an iron chain deposited on top of Au/Nb
heterostructure. As a continuation of the first part of the paper
experimentally relevant computational experiments are performed in spin spiral
chains that shed light on several concerns about practical applications and add
new aspects to the interpretation of recent experiments. We explore the
stability of topological zero energy states, the formation and distinction of
topologically trivial and non-trivial zero energy edge states, the effect of
local changes in the exchange fields, the emergence of topological
fragmentation, and the shift of Majorana Zero Modes along the superconducting
nanowires opening avenues toward the implementation of a braiding operation.
The pursuit of room-temperature ambient-pressure superconductivity in novel
materials has sparked interest, with recent reports suggesting such properties
in Cu-substituted lead apatite, known as LK-99. However, these claims lack
comprehensive experimental and theoretical support. In this study, we address
this gap by conducting ab initio calculations to explore the impact of varying
doping concentrations (x = 0, 1, 2) on the stability and electronic properties
of five compounds in the LK-99 family. Our investigations unveil a distinct
feature within LK-99: isolated flat bands that intersect the Fermi level. In
contrast, the other four compounds exhibit insulating behavior with wide band
gaps. X-ray diffraction analyses confirm the presence of Cu substitution on
Pb(1) sites in the originally synthesized LK-99 sample, while an extra peak
suggests potential alternative phases like Pb$_8$Cu$_2$(PO$_4$)$_6$ due to
compositional variations. Furthermore, the LK-99 structure undergoes
substantial lattice constriction, resulting in a significant 5.5% reduction in
volume. Meanwhile, energy calculations reveal a marginal energy preference for
substituting Cu on Pb(2) sites over Pb(1) sites, with a difference of
approximately 0.010 eV per atom (roughly 1 kJ/mol). Intriguingly, at pressures
exceeding 73 GPa, stability shifts towards LK-99 containing Cu substitutions on
Pb(1) sites. Despite exhibiting higher electronic conductivity than parent
compounds, LK-99 falls short of the conductivity levels observed in metals or
advanced oxide conductors.
Electron states with the spin-momentum-locked Dirac dispersion at the surface
of a three-dimensional (3D) topological insulator are known to lead to weak
antilocalization (WAL), i.e. low temperature and low-magnetic field quantum
interference-induced positive magnetoresistance (MR). In this work we report on
the MR measurements in (Bi,Sb)$_2$(Te,Se)$_3$ 3D topological insulator thin
films epitaxially grown on Si(111), demonstrating an anomalous WAL amplitude.
This anomalously high amplitude of WAL can not be explained by parabolic or
linear MR and indicates the existence of an additional, MR mechanism. Another
supporting observation is not linear in the classically weak magnetic field
Hall effect in the same films. The increase of the low-field Hall coefficient,
with respect to the higher-field value, reaches 10$\%$. We consistently explain
both transport features within a two-liquid model, where the mobility of one of
the components drops strongly in a weak magnetic field. We argue that this
dependence may arise from the Zeeman field induced gap opening mechanism.
Surface diffusion on metal oxides is key in many areas of materials
technology, yet it has been scarcely explored at the atomic scale. This work
provides phenomenological insights from scanning tunneling microscopy on the
link between surface diffusion, surface atomic structure, and oxygen chemical
potential based on three model oxide surfaces: Fe$_2$O$_3(1\overline{1}02)$,
La$_{1-x}$Sr$_x$MnO$_3$(110), and In$_2$O$_3$(111). In all instances, changing
the oxygen chemical potential used for annealing stabilizes reconstructions of
different compositions while promoting the flattening of the surface morphology
-- a sign of enhanced surface diffusion. It is argued that thermodynamics,
rather than kinetics, rules surface diffusion under these conditions: The
composition change of the surface reconstructions formed at differently
oxidizing conditions drives mass transport across the surface.
A topological phase can be engineered in quantum physics from the Bloch
sphere of a spin-1/2 showing an hedgehog structure as a result of a radial
magnetic field. We elaborate on a relation between the formation of an
entangled wavefunction at one pole, in a two-spins model, and an interesting
pair of one-half topological numbers. Similar to Cooper pairs in
superconductors, the Einstein-Podolsky-Rosen pair or Bell state produces a half
flux quantization, which here refers to the halved flux of the Berry curvature
on the surface. These 1/2-numbers also reveal the presence of a free Majorana
fermion at a pole. The topological responses can be measured when driving from
north to south and also from a circularly polarized field at the poles
revealing the quantized or half-quantized nature of the protected transverse
currents. We show applications of entangled wavefunctions in band structures,
introducing a local topological marker in momentum space, to characterize the
topological response of two-dimensional semimetals in bilayer geometries.
Recent years witnessed the development of powerful generative models based on
flows, diffusion or autoregressive neural networks, achieving remarkable
success in generating data from examples with applications in a broad range of
areas. A theoretical analysis of the performance and understanding of the
limitations of these methods remain, however, challenging. In this paper, we
undertake a step in this direction by analysing the efficiency of sampling by
these methods on a class of problems with a known probability distribution and
comparing it with the sampling performance of more traditional methods such as
the Monte Carlo Markov chain and Langevin dynamics. We focus on a class of
probability distribution widely studied in the statistical physics of
disordered systems that relate to spin glasses, statistical inference and
constraint satisfaction problems.
We leverage the fact that sampling via flow-based, diffusion-based or
autoregressive networks methods can be equivalently mapped to the analysis of a
Bayes optimal denoising of a modified probability measure. Our findings
demonstrate that these methods encounter difficulties in sampling stemming from
the presence of a first-order phase transition along the algorithm's denoising
path. Our conclusions go both ways: we identify regions of parameters where
these methods are unable to sample efficiently, while that is possible using
standard Monte Carlo or Langevin approaches. We also identify regions where the
opposite happens: standard approaches are inefficient while the discussed
generative methods work well.
A van der Waals material, MoTe2 with a monoclinic 1T' crystal structure is a
candidate for three-dimensional (3D) second-order topological insulators
(SOTIs) hosting gapless hinge states and insulating surface states. However,
due to the temperature-induced structural phase transition, the monoclinic 1T'
structure of MoTe2 would be transformed into the orthorhombic Td structure as
the temperature is lowered, which hinders the experimental verification and the
electronic applications of the predicted SOTI state at low temperatures. Here,
we present systematic Raman spectroscopy studies of the exfoliated MoTe2 thin
flakes with variable thicknesses at different temperatures. As a spectroscopic
signature of the orthorhombic Td structure of MoTe2, the out-of-plane vibration
mode D at ~ 125 cm-1 is always visible below a certain temperature in the
multilayer flakes thicker than ~ 27.7 nm, but vanishes in the temperature range
from 80 K to 320 K when the flake thickness becomes lower than ~ 19.5 nm. The
absence of the out-of-plane vibration mode D in the Raman spectra here
demonstrates not only the disappearance of the monoclinic-to-orthorhombic phase
transition but also the persistence of the monoclinic 1T' structure in the
MoTe2 thin flakes thinner than ~ 19.5 nm at low temperatures down to 80 K,
which may be caused by the high enough density of the holes introduced during
the gold-enhanced exfoliation process and exposure to air. The MoTe2 thin
flakes with the low-temperature monoclinic 1T' structure provide a material
platform for realizing SOTI states in van der Waals materials at low
temperatures, which paves the way for developing a new generation of electronic
devices based on SOTIs.
Higher-order networks are gaining growing attention as they encode for the
many-body interactions present in complex systems. However, higher-order
networks have the limitation that they only capture many-body interactions of
the same type. To tackle this challenge, here we provide a mathematical
framework to capture the topology of higher-order multiplex networks and the
interplay between their topology and higher-order dynamics. In particular we
focus on diffusion of topological signals sustained not only by the nodes, but
also by the links, and the higher-dimensional simplices of multiplex simplicial
complexes. We exploit the ubiquitous presence of the overlap of the simplices
for coupling the dynamics among the multiplex layers providing a definition of
multiplex Hodge Laplacians and Dirac operators. The spectral properties of
these operators are shown to determine the higher-order diffusion on the
higher-order multiplex networks, and encode for the multiplex Betti numbers.
Finally, our numerical investigation of the spectral properties of synthetic
and real (connectome and microbiome) multiplex simplicial complexes shows
evidence that the coupling between the layers can either speed up or slow down
the higher-order diffusion of topological signals. This mathematical framework
is very general and can be applied to study generic higher-order systems with
interactions of multiple types. In particular, these results might find
applications in brain networks which are understood to be both multilayer and
higher-order.
Topological magnetic (anti)skrymions are robust string-like objects heralded
as potential components in next-generation topological spintronics devices due
to their manipulability via low-energy stimuli such as magnetic fields, heat,
and electric/thermal current. While these two-dimensional (2D) topological
objects are widely studied, intrinsically three-dimensional (3D) electron-spin
real-space topology remains less explored despite its prevalence in bulky
magnets. Here, we capture the 3D structure of antiskyrmions in a
single-crystal, precision-doped (Fe_{0.63}Ni_{0.3}Pd_{0.07})_{3}P lamellae
using holographic vector field electron tomography at room temperature and zero
field. Our measurements reveal hybrid string-like solitons composed of
skyrmions with topological number W = -1 on the lamellae's surfaces and an
antiskyrmion (W = +1) connecting them. High resolution images uncover a Bloch
point (BP) quadrupole (four magnetic (anti)monopoles) positioned along the
rectangular antiskyrmion's four corners (Bloch lines), which enable the
observed lengthwise topological transitions. Furthermore, we calculate and
compare the energy densities of hybrid strings with ideal (anti)skyrmion
strings using micromagnetic simulations, which suggest that this composite
(anti)BP structure stabilizes via the subtle interplay between the
magnetostatic interaction and anisotropic Dzyaloshinskii-Moriya interaction.
The discovery of these hybrid spin textures enables topological tunabilty, a
tunable topological Hall effect, and the suppression of skyrmion Hall motion,
disrupting existing paradigms within spintronics.
We have studied in detail the $M$-$p$ balanced spin glass model, which is a
candidate for being a model for structural glasses. Such models possess two
kinds of broken replica states; those with one-step replica symmetry breaking
(1RSB) and those with full replica symmetry breaking (FRSB). To determine which
arises requires studying the Landau expansion to quintic order. There are 9
quintic order coefficients, and 5 quartic order coefficients, whose values we
determine for this model. We show that it is only for $2 \leq M < 2.4714
\cdots$ that the transition at mean-field level is to a state with FRSB, while
for larger $M$ values there is either a continuous transition to a state with
1RSB (when $ M \leq 3$) or a discontinuous transition for $M > 3$. The Gardner
transition from a 1RSB state at low temperatures to a state with FRSB also
requires the Landau expansion to be taken to quintic order. Our result for the
form of FRSB in the Gardner phase is similar to that found when $2 \leq M <
2.4714\cdots$, but differs from that given in the early paper of Gross et al.
[Phys. Rev. Lett. 55, 304 (1985)]. Finally we discuss the effects of
fluctuations on our mean-field solutions using the scheme of H\"{o}ller and
Read [Phys. Rev. E 101, 042114 (2020)] and argue that such fluctuations will
remove the continuous 1RSB transition in dimension $d$ when $8 >d \geq 6$
leaving just the FRSB continuous transition (and possibly also the
discontinuous 1RSB transition). We suggest values for $M$ and $p$ which might
be used in simulations to resolve the outstanding question of whether
fluctuation corrections can remove the discontinuous 1RSB transition.
When electrons moving in two-dimensions (2D) are subjected to a strong
uniform magnetic field, they form flat bands called Landau levels, which are
the basis for the quantum Hall effect. Landau levels can also arise from
pseudomagnetic fields (PMFs) induced by lattice distortions; for example,
mechanically straining graphene causes its Dirac quasiparticles to form a
characteristic set of unequally-spaced Landau levels, including a zeroth Landau
level. In three-dimensional (3D) systems, there has thus far been no
experimental demonstration of Landau levels or any other type of flat band. For
instance, applying a uniform magnetic field to materials hosting Weyl
quasiparticles, the 3D generalizations of Dirac quasiparticles, yields bands
that are non-flat in the direction of the field. Here, we report on the
experimental realization of a flat 3D Landau level in an acoustic crystal.
Starting from a lattice whose bandstructure exhibits a nodal ring, we design an
inhomogeneous distortion corresponding to a specific pseudomagnetic vector
potential (PVP) that causes the nodal ring states to break up into Landau
levels, with a zeroth Landau level that is flat along all three directions.
These findings point to the possibility of using nodal ring materials to
generate 3D flat bands, to access strong interactions and other interesting
physical regimes in 3D.
Since the discovery of the fascinating properties in magic-angle graphene,
the exploration of moir\'e systems in other two-dimensional materials has
garnered significant attention and given rise to a field known as 'moir\'e
physics'. Within this realm, magnetic van der Waals heterostructure and the
magnetic proximity effect in moir\'e superlattices have also become subjects of
great interest. However, the spin-polarized transport property in this moir\'e
structures is still a problem to be explored. Here, we investigate the
spin-polarized transport properties in a moir\'e superlattices formed by a
two-dimensional ferromagnet CrI_3 stacked on a monolayer BAs, where the spin
degeneracy is lifted because of the magnetic proximity effect associated with
the moir\'e superlattices. We find that the conductance exhibits spin-resolved
miniband transport properties at a small twist angle because of the periodic
moir\'e superlattices. When the incident energy is in the spin-resolved
minigaps, the available states are spin polarized, thus providing a
spin-polarized current from the superlattice. Moreover, only a finite number of
moir\'e period is required to obtain a net spin polarization of 100\%. In
addition, the interlayer distance of the heterojunction is also moir\'e
modifiable, so a perpendicular electric field can be applied to modulate the
intensity and direction of the spin polarization. Our finding points to an
opportunity to realize spin functionalities in magnetic moir\'e superlattices.
Kagome magnets showing diverse topological quantum responses are crucial for
next-generation topological engineering. Here we report the physical properties
of a newly discovered titanium-based Kagome ferromagnet SmTi3Bi4, mainly
focusing on its anisotropy and high-pressure tunability of magnetism. The
crystal structure of SmTi3Bi4 belongs to the RETi3Bi4 (RE = Rare earth element)
prototype, featuring a distorted Ti Kagome lattice in TiBi layer and Sm-atomic
zig-zag chain along the c axis. By the temperature-dependent resistivity, heat
capacity, and magnetic susceptibility measurements, a ferromagnetic (FM)
ordering temperature Tc is determined to be 23.2 K, above which a T-linear
resistivity and quite large density of states near Fermi level are hinted to
exist. A large magnetic anisotropy was observed by rotating the in-plane
magnetic field, showing the b axis is the easy magnetizations axis. The
resistance under high pressure shows a suppression from 23.2 K to 8.5 K up to
23.5 GPa first and a following little enhancement up to 44.8 GPa. Considering
the large in-plane magnetization between stacked Kagome lattices and tunability
of FM order, possible topological phase transitions can be anticipated in
SmTi3Bi4, which should be a new promising platform to explore the complex
electronic and magnetic phases based on Kagome lattice.
The potential for low-threshold optical nonlinearity has received significant
attention in the fields of photonics and conceptual optical neuron networks.
Excitons in two-dimensional (2D) semiconductors are particularly promising in
this regard as reduced screening and dimensional confinement foster their
pronounced many-body interactions towards nonlinearity. However, experimental
determination of the interactions remains ambiguous, as optical pumping in
general creates a mixture of excitons and unbound carriers, where the impacts
of band gap renormalization and carrier screening on exciton energy counteract
each other. Here by comparing the influences on exciton ground and excited
states energies in the photoluminescence spectroscopy of monolayer MoSe$_2$, we
are able to identify separately the screening of Coulomb binding by the neutral
excitons and by charge carriers. The energy difference between exciton ground
state (A-1s) and excited state (A-2s) red-shifts by 5.5 meV when the neutral
exciton density increases from 0 to $4\times 10^{11}$ cm$^{-2}$, in contrast to
the blue shifts with the increase of either electron or hole density. This
energy difference change is attributed to the mutual screening of Coulomb
binding of neutral excitons, from which we extract an exciton polarizability of
$\alpha_{2D}^{\rm exciton} = 2.55\times 10^{-17}$ eV(m/V)$^2$. Our finding
uncovers a new mechanism that dominates the repulsive part of many-body
interaction between neutral excitons.
Two-dimensional (2D) materials tend to have the preferably formation of
vacancies at the outer surface. Here, contrary to the normal notion, we reveal
a type of vacancy that thermodynamically initiates from the interior part of
the 2D backbone of germanium selenide ({\gamma}-GeSe). Interestingly, the
Ge-vacancy (VGe) in the interior part of {\gamma}-GeSe possesses the lowest
formation energy amongst the various types of defects considered. We also find
a low diffusion barrier (1.04 eV) of VGe which is a half of those of sulfur
vacancy in MoS2. The facile formation of mobile VGe is rooted in the
antibonding coupling of the lone-pair Ge 4s and Se 4p states near the valence
band maximum, which also exists in other gamma-phase MX (M=Sn, Ge; X=S, Te).
The VGe is accompanied by a shallow acceptor level in the band gap and induces
strong infrared light absorption and p-type conductivity. The VGe located in
the middle cationic Ge sublattice is well protected by the surface Se layers-a
feature that is absent in other atomically thin materials. Our work suggests
that the unique well-buried inner VGe, with the potential of forming
structurally protected ultrathin conducting filaments, may render the GeSe
layer an ideal platform for quantum emitting, memristive, and neuromorphic
applications.
Nitrate reduction to ammonia has attracted much attention for nitrate (NO3-)
removal and ammonia (NH3) production. Identifying promising catalyst for active
nitrate electroreduction reaction (NO3RR) is critical to realize efficient
upscaling synthesis of NH3 under low-temperature condition. For this purpose,
by means of spin-polarized first-principles calculations, the NO3RR performance
on a series of graphitic carbon nitride (g-CN) supported double-atom catalysts
(denoted as M1M2@g-CN) are systematically investigated. The synergistic effect
of heterogeneous dual-metal sites can bring out tunable activity and
selectivity for NO3RR. Amongst 21 candidates examined, FeMo@g-CN and CrMo@g-CN
possess a high performance with low limiting potentials of -0.34 and -0.39 V,
respectively. The activities can be attributed to a synergistic effect of the
M1M2 dimer d orbitals coupling with the anti-bonding orbital of NO3-. The
dissociation of deposited FeMo and CrMo dimers into two separated monomers is
proved to be difficult, ensuring the kinetic stability of M1M2@g-CN.
Furthermore, the dual-metal decorated on g-CN significantly reduces the bandgap
of g-CN and broadens the adsorption window of visible light, implying its great
promise for photocatalysis. This work opens a new avenue for future theoretical
and experimental design related to NO3RR photo-/electrocatalysts.
Kagome materials have attracted a surge of research interest recently,
especially for the ones combining with magnetism, and the ones with weak
interlayer interactions which can fabricate thin devices. However, kagome
materials combining both characters of magnetism and weak interlayer
interactions are rare. Here we investigate a new family of titanium based
kagome materials RETi3Bi4 (RE = Eu, Gd and Sm). The flakes of nanometer
thickness of RETi3Bi4 can be obtained by exfoliation due to the weak interlayer
interactions. According to magnetic measurements, out-of-plane ferromagnetism,
out-of-plane anti-ferromagnetism, and in-plane ferromagnetism are formed for RE
= Eu, Gd, and Sm respectively. The magnetic orders are simple and the
saturation magnetizations can be relatively large since the rare earth elements
solely provide the magnetic moments. Further by angle-resolved photoemission
spectroscopy (ARPES) and first-principles calculations, the electronic
structures of RETi3Bi4 are investigated. The ARPES results are consistent with
the calculations, indicating the bands characteristic with kagome sublattice in
RETi3Bi4. We expect these materials to be promising candidates for observation
of the exotic magnetic topological phases and the related topological quantum
transport studies.
The topological properties of the Su-Schrieffer-Heeger (SSH) model in the
presence of nearest-neighbor interaction are investigated by means of a
topological marker, generalized from a noninteracting one by utilizing the
single-particle Green's function of the many-body ground state. We find that
despite the marker not being perfectly quantized in the presence of
interactions, it always remains finite in the topologically nontrivial phase
while converging to zero in the trivial phase when approaching the
thermodynamic limit, and hence correctly judges the topological phases in the
presence of interactions. The marker also correctly captures the
interaction-driven, second-order phase transitions between a topological phase
and a Landau-ordered phase, which is a charge density wave order in our model
with a local order parameter, as confirmed by the calculation of entanglement
entropy and the many-body Zak phase. Our work thus points to the possibility of
generalizing topological markers to interacting systems through Green's
function, which may be feasible for topological insulators in any dimension and
symmetry class.
Magnetic nanoparticles (MNPs) have many applications which require MNPs to be
captured and immobilized for their manipulation and sensing. For example, MNP
sensors based on detecting changes to the ferromagnetic resonances of an
antidot nanostructure exhibit better performance when the nanoparticles are
captured within the antidot inclusions. This study investigates the influence
of microfluidics upon the capture of MNPs by four geometries of antidot array
nanostructures hollowed into 30 nm-thick Permalloy films. The nanostructures
were exposed to a dispersion of 130 nm MNP clusters which passed through PDMS
microfluidic channels with a 400 {\mu}m circular cross-section fabricated from
wire molds. With the microfluidic flow of MNPs, the capture efficiency - the
ratio between the number of nanoparticles captured inside of the antidot
inclusions to the number outside the inclusions - decreased for all four
geometries compared to previous results introducing the particles via droplets
on the film surface. This indicates that most MNPs were passing over the
nanostructures, since there were no significant magnetophoretic forces acting
upon the particles. However, when a static magnetic field is applied, the
magnetophoretic forces generated by the nanostructure are stronger and the
capture efficiencies are significantly higher than those obtained using
droplets. In particular, circular antidots demonstrated the highest capture
efficiency among the four geometries of almost 83.1% when the magnetic field is
parallel to the film plane. In a magnetic field perpendicular to the film, the
circle antidots again show the highest capture efficiency of about 77%. These
results suggest that the proportion of nanoparticles captured inside antidot
inclusions is highest under a parallel magnetic field. Clearly, the geometry of
the nanostructure has a strong influence on the capture of MNPs.
The one-dimensional (1D) Su-Schrieffer-Heeger (SSH) model is central to band
topology in condensed matter physics, which allows us to understand and design
topological states. The Su-Schrieffer-Heeger (SSH) model serves as a basis for
topological insulators and provides insights into various topological states.
In this letter, we find another mechanism to analogize the SSHmodel by
introducing intrinsic spin-orbital coupling (SOC) and in-plane Zeeman field
instead of relying on alternating hopping integrals. In our model, the bound
states are protected by a quantizedhidden polarization andcharacterized by a
weak Z2 index (0;01) due to the inversion symmetry I. When the I symmetry is
broken, charge pumping is achieved by tuning the polarization. Moreover, by
introducing the p + ip superconductor pairing potential, a new topological
phase called weak topological superconductor (TSC) is identified. The new TSC
is characterized by a weak Z2 index (0;01) and nonchiral bound states. More
interestingly, these nonchiral bound states give rise to a chiral nonlocal
conductance, which is different from the traditional chiral TSC. Our findings
not only innovate the SSH model, but also predict the existence of weak TSC,
providing an alternative avenue for further exploration of its transport
properties.
Twisted bilayers of transition metal dichalcogenides (TMDs) have revealed a
rich exciton landscape including hybrid excitons and spatially trapped moir\'e
excitons that dominate the optical response of the material. Recent studies
have revealed that in the low-twist-angle regime, the lattice undergoes a
significant relaxation in order to minimize local stacking energies. Here,
large domains of low energy stacking configurations emerge, deforming the
crystal lattices via strain and consequently impacting the electronic band
structure. However, so far the direct impact of atomic reconstruction on the
exciton energy landscape and the optical properties has not been well
understood. Here, we apply a microscopic and material-specific approach and
predict a significant change in the potential depth for moir\'e excitons in a
reconstructed lattice, with the most drastic change occurring in TMD
homobilayers. We reveal the appearance of multiple flat bands and a significant
change in the position of trapping sites compared to the rigid lattice. Most
importantly, we predict a multi-peak structure emerging in optical absorption
of WSe$_2$ homobilayers - in stark contrast to the single peak that dominates
the rigid lattice. This finding can be exploited as an unambiguous signature of
atomic reconstruction in optical spectra of moir\'e excitons in twisted
homobilayers.
In the context of $\theta$ electrodynamics we find transverse electromagnetic
wave solutions forbidden in Maxwell electrodynamics. Our results attest to new
evidence of the topological magnetoelectric effect in topological insulators,
resulting from a polarization rotation of an external electromagnetic field.
Unlike Faraday and Kerr rotations, the effect does not rely on a longitudinal
magnetic field, the reflected field, or birefringence. The rotation occurs due
to transversal discontinuities of the topological magnetoelectric parameter in
cylindrical geometries. The dispersion relation is linear, and birefringence is
absent. One solution behaves as an optical fiber confining exact transverse
electromagnetic fields with omnidirectional reflectivity. These results may
open new possibilities in optics and photonics by utilizing topological
insulators to manipulate light.
Quantum transport across discrete structures is a relevant topic of solid
state physics and quantum information science, which can be suitably studied in
the context of continuous-time quantum walks. The addition of phases degrees of
freedom, leading to chiral quantum walks, can also account for directional
transport on graphs with loops. We discuss criteria for quantum transport and
study the enhancement that can be achieved with chiral quantum walks on
chain-like graphs, exploring different topologies for the chain units and
optimizing over the phases. We select three candidate structures with optimal
performance and investigate their transport behaviour with Krylov reduction.
While one of them can be reduced to a weighted line with minor couplings
modulation, the other two are truly chiral quantum walks, with enhanced
transport probability over long chain structures.
Owing to its atomically thin thickness, layer-dependent tunable band gap,
flexibility, and CMOS compatibility, MoS$_2$ is a promising candidate for
photodetection. However, mono-layer MoS2-based photodetectors typically show
poor optoelectronic performances, mainly limited by their low optical
absorption. In this work, we hybridized CVD-grown monolayer MoS$_2$ with a gold
nanodisk (AuND) array to demonstrate a superior visible photodetector through a
synergetic effect. It is evident from our experimental results that there is a
strong light-matter interaction between AuNDs and monolayer MoS$_2$, which
results in better photodetection due to a surface trap state passivation with a
longer charge carrier lifetime compared to pristine MoS$_2$. In particular, the
AuND/MoS$_2$ system demonstrated a photoresponsivity of $8.7 \times 10^{4}$
A/W, specific detectivity of $6.9 \times 10^{13}$ Jones, and gain $1.7 \times
10^{5}$ at $31.84 \mu W/cm^{2}$ illumination power density of 632 nm wavelength
with an applied voltage of 4.0 V for an AuND/MoS$_2$-based photodetector. To
our knowledge, these optoelectronic responses are one order higher than
reported results for CVD MoS$_2$-based photodetector in the literature.
Direct detection of relic neutrinos in a beta-decay experiment is an
ambitious goal, which has for a long time been beyond the reach of available
technology. One of the toughest practical difficulties that such an experiment
has to overcome is that it needs to deal with a large amount of radioactive
material in such a way as to not compromise the energy resolution required for
the separation of useful events from the massive beta-decay background. The
PTOLEMY project offers an innovative approach to this problem based on
deposition of radioactive material on graphene. While such an approach is
expected to resolve the main difficulty, new challenges arise from the
proximity of the beta decayers to a solid state system. In this work, we focus
on the effect of the shakeup of the graphene electron system due to a
beta-decay event. We calculate the distortion of the relic neutrino peaks as
resulting from such a shakeup, analyse the impact of the distortion on the
visibility of neutrino capture events and discuss what technological solutions
could be used to improve the visibility of neutrino capture events.
The layered transition metal dichalcogenide compounds 1T-TaS2 and 4H-TaS2 are
well known for their exotic properties, which include charge density wave,
superconductivity, Mott transition, etc., and lately quantum spin liquid. Here,
we report the magnetic, transport and transmission electron microscopy study of
the charge density wave and superconductivity in 6R-TaS2 which is a relatively
less studied polymorph of this dichalcogenide TaS2. Our high temperature
electron microscopy reveals multiple charge density wave transitions between
room temperature and 650K. Magnetization, and the electrical resistivity
measurements in the temperature range of 2-400 K reveal that 6R-TaS2 undergoes
a charge density wave transition around 305 K and is followed by a transition
to a superconducting state around 3.5 K. The low temperature specific heat
measurement exhibits anomaly associated with the superconducting transition
around 2.4 K. The estimated Ginzburg Landau parameter suggests that this
compound lies at the extreme limit of type-II superconductivity.
Multipolar Kondo systems offer unprecedented opportunities for designing
astonishing quantum phases and functionalities beyond spin-only descriptions. A
model material platform of this kind is the cubic heavy-fermion system
Pr$Tr_{2}$Al$_{20}$ ($Tr=$ Ti, V), which hosts a nonmagnetic
crystal-electric-field (CEF) ground state and substantial Kondo entanglement of
the local quadrupolar and octopolar moments with the conduction electron sea.
Here, we explore magnetoresistance (MR) and Hall effect of PrTi$_{2}$Al$_{20}$
that develops ferroquadrupolar (FQ) order below $T_{Q} \sim 2$ K and compare
its behavior with that of the non-4$f$ analog, LaTi$_{2}$Al$_{20}$. In the FQ
ordered phase, PrTi$_{2}$Al$_{20}$ displays extremely large magnetoresistance
(XMR) of $\sim 10^{3}\%$. The unsaturated, quasi-linear field ($B$) dependence
of the XMR violates the conventional Kohler's scaling and defies description
based on carrier compensation alone. By comparing the MR and the Hall effect
observed in PrTi$_{2}$Al$_{20}$ and LaTi$_{2}$Al$_{20}$, we conclude that the
open-orbit topology on the electron-type Fermi surface (FS) sheet is key for
the observed XMR. The low-temperature MR and the Hall resistivity in
PrTi$_{2}$Al$_{20}$ display pronounced anisotropy in the [111] and [001]
magnetic fields, which is absent in LaTi$_{2}$Al$_{20}$, suggesting that the
transport anisotropy ties in with the anisotropic magnetic-field response of
the quadrupolar order parameter.
By monitoring the quality factor of a quartz tuning fork oscillator we have
observed a fluctuation-driven reduction in the viscosity of bulk $^3$He in the
normal state near the superfluid transition temperature, $T_c$. These
fluctuations, which are only found within $100 \mu$K of $T_c$, play a vital
role in the theoretical modeling of ordering; they encode details about the
Fermi liquid parameters, pairing symmetry, and scattering phase shifts. They
will be of crucial importance for transport probes of the topologically
nontrivial features of superfluid $^3$He under strong confinement. Here we
characterize the temperature and pressure dependence of the fluctuation
signature, finding data collapse consistent with the predicted theoretical
behavior.
The valence electronic structure of magnetic centers is one of the factors
that determines the characteristics of a magnet. It may refer to orbital
degeneracy, as for $j_\text{eff}=1/2$ Kitaev magnets, or near-degeneracy, e.g.
involving the third and fourth shells in cuprate superconductors. Here we
explore the inner structure of magnetic moments in group-5 lacunar spinels,
fascinating materials featuring multisite magnetic units in the form of
tetrahedral tetramers. Our quantum chemical analysis reveals a very colorful
landscape, much richer than the single-electron, single-configuration
description applied so far to all group-5 Ga$M_4X_8$ chalcogenides, and
clarifies the basic multiorbital correlations on $M_4$ tetrahedral clusters:
while for V strong correlations yield a wave-function that can be well
described in terms of four V$^{4+}$V$^{3+}$V$^{3+}$V$^{3+}$ resonant valence
structures, for Nb and Ta a picture of dressed molecular-orbital-like
$j_\text{eff}=3/2$ entities is more appropriate. These internal degrees of
freedom likely shape vibronic couplings, phase transitions, and
magneto-electric properties in each of these systems.
Among the variety of correlated states exhibited by twisted bilayer graphene,
cascades in the spectroscopic properties and in the electronic compressibility
occur over larger ranges of energy, twist angle and temperature compared to
other effects. This suggests a hierarchy of phenomena. Using combined dynamical
mean-field theory and Hartree calculations, we show that the spectral weight
reorganisation associated with the formation of local moments and heavy
quasiparticles can explain the cascade of electronic resets without invoking
symmetry breaking orders. The phenomena reproduced here include the cascade
flow of spectral weight, the oscillations of remote band energies, and the
asymmetric jumps of the inverse compressibility. We also predict a strong
momentum differentiation in the incoherent spectral weight associated with the
fragile topology of twisted bilayer graphene.
A multitask deep neural network model was trained on more than 218k different
glass compositions. This model, called GlassNet, can predict 85 different
properties (such as optical, electrical, dielectric, mechanical, and thermal
properties, as well as density, viscosity/relaxation, crystallization, surface
tension, and liquidus temperature) of glasses and glass-forming liquids of
different chemistries (such as oxides, chalcogenides, halides, and others). The
model and the data used to train it are available in the GlassPy Python module
as free and open source software for the community to use and build upon. As a
proof of concept, GlassNet was used with the MYEGA viscosity equation to
predict the temperature dependence of viscosity and outperformed another
general purpose viscosity model available in the literature (ViscNet) on unseen
data. An explainable AI algorithm (SHAP) was used to extract knowledge
correlating the input (physicochemical information) and output (glass
properties) of the model, providing valuable insights for glass manufacturing
and design. It is hoped that GlassNet, with its free and open source nature,
can be used to enable faster and better computer-aided design of new
technological glasses.
The sine-Gordon model emerges as a low-energy theory in a plethora of quantum
many-body systems. Here, we theoretically investigate tunnel-coupled
Bose-Hubbard chains with strong repulsive interactions as a realization of the
sine-Gordon model deep in the quantum regime. We propose protocols for quantum
gas microscopes of ultracold atoms to prepare and analyze solitons, that are
the fundamental topological excitations of the emergent sine-Gordon theory.
With numerical simulations based on matrix product states we characterize the
preparation and detection protocols and discuss the experimental requirements.
Intrinsic topological superconducting materials are exotic and vital to
develop the next-generation topological superconducting devices, topological
quantum calculations, and quantum information technologies. Here, we predict
the topological and nodal superconductivity of MS (M = Nb and Ta)
transition-metal sulfides by using the density functional theory for
superconductors combining with the symmetry indicators. We reveal their
higher-order topology nature with an index of Z4 = 2. These materials have a
higher Tc than the Nb or Ta metal superconductors due to their flat-band and
strong electron-phonon coupling nature. Electron doping and lighter isotopes
can effectively enhance the Tc. Our findings show that the MS (M = Nb and Ta)
systems can be new platforms to study exotic physics in the higher-order
topological superconductors, and provide a theoretical support to utilize them
as the topological superconducting devices in the field of advanced topological
quantum calculations and information technologies.
The interplay between competing degrees of freedom can stabilize non-trivial
magnetic states in correlated electron materials. Frustration-induced strong
quantum fluctuations can evade long-range magnetic ordering leading to exotic
quantum states such as spin liquids in two-dimensional spin-lattices such as
triangular and kagome structures. However, the experimental realization of
dynamic and correlated quantum states is rare in three-dimensional (3D)
frustrated magnets wherein quantum fluctuations are less prominent. Herein, we
report the crystal structure, magnetic susceptibility, electron spin resonance
(ESR) and specific heat studies accompanied by crystal electric field (CEF)
calculations on a 3D frustrated magnet Yb3Sc2Ga3O12. In this material, Yb3+
ions form a three-dimensional network of corner-sharing triangles known as
hyperkagome lattice without any detectable anti-site disorder. Our results
reveal a low energy state with Jeff = 1/2 degrees of freedom in the Kramers
doublet state. The zero field-cooled and field cooled magnetic susceptibility
taken in 0.001 T rules out the presence of spin-freezing down to 1.8K. The
Curie-Weiss (CW) fit to low-T susceptibility data yields a small and negative
CW temperature indicating the presence of a weak antiferromagnetic interaction
between Jeff = 1/2 (Yb3+) moments. The Yb-ESR displays a broad line of
non-Lorentzian shape that suggests considerable magnetic anisotropy in
Yb3Sc2Ga3O12. The CEF calculations suggest that the ground state is well
separated from the excited states, which are in good agreement with
experimental results. The absence of long-range magnetic ordering indicates a
dynamic liquid-like ground state at least down to 130 mK. Furthermore, zero
field specific heat shows a broad maximum around 200 mK suggesting the presence
of short-range spin correlations in this 3D frustrated antiferromagnet.
Laser-driven coherent phonons can act as modulated strain fields and modify
the adiabatic ground state topology of quantum materials. Here we use
time-dependent first-principles and effective model calculations to simulate
the effect of the coherent phonon induced by strong terahertz electric field on
electronic carriers in the topological insulator ZrTe$_5$. We show that a
coherent $A_\text{1g}$ Raman mode modulation can effectively pump carriers
across the band gap, even though the phonon energy is about an order of
magnitude smaller than the equilibrium band gap. We reveal the microscopic
mechanism of this effect which occurs via Landau-Zener-St\"uckelberg tunneling
of Bloch electrons in a narrow region in the Brillouin zone center where the
transient energy gap closes when the system switches from strong to weak
topological insulator. The quantum dynamics simulation results are in excellent
agreement with recent pump-probe experiments in ZrTe$_5$ at low temperature.
During embryonic development, structures with complex geometry can emerge
from planar epithelial monolayers and to study these shape transitions is of
key importance for revealing the biophysical laws involved in the morphogenesis
of biological systems. Here, using the example of normal proliferative monkey
kidney (COS) cell monolayers, we investigate global and local topological
characteristics of this model system in dependence on its shape. The obtained
distributions of cells by their valence demonstrate a previously undetected
difference between the spherical and planar monolayers. In addition, in both
spherical and planar monolayers, the probability to observe a pair of
neighboring cells with certain valences depends on the topological charge of
the pair. The zero topological charge of the cell pair can increase the
probability for the cells to be the nearest neighbors. We then test and confirm
that analogous relationships take place in a more ordered spherical system with
a larger fraction of 6-valent cells, namely in the non-proliferative epithelium
(follicular system) of ascidian species oocytes. However, unlike spherical COS
cell monolayers, ascidian monolayers are prone to non-random agglomeration of
6-valent cells and have linear topological defects called scars and pleats. The
reasons for this difference in morphology are discussed. The morphological
peculiarities found are compared with predictions of widely used vertex model
of epithelium.
We consider a system of interacting spinless fermions on a two-leg triangular
ladder with $\pi/2$ magnetic flux per triangular plaquette. Microscopically,
the system exhibits a U(1) symmetry corresponding to the conservation of total
fermionic charge, and a discrete $\mathbb{Z}_2$ symmetry -- a product of parity
transformation and chain permutation. Using bosonization, we show that, in the
low-energy limit, the system is described by the quantum double-frequency
sine-Gordon model. On the basis of this correspondence, a rich phase diagram of
the system is obtained. It includes trivial and topological band insulators for
weak interactions, separated by a Gaussian critical line, whereas at larger
interactions a strongly correlated phase with spontaneously broken
$\mathbb{Z}_2$ symmetry sets in, exhibiting a net charge imbalance and non-zero
total current. At the intersection of the three phases, the system features a
critical point with an emergent SU(2) symmetry. This non-Abelian symmetry,
absent in the microscopic description, is realized at low-energies as a
combined effect of the magnetic flux, frustration, and many-body correlations.
The criticality belongs to the SU(2)$_1$ Wess-Zumino-Novikov-Witten
universality class. The critical point bifurcates into two Ising critical lines
that separate the band insulators from the strong-coupling symmetry broken
phase. We establish an analytical connection between the low-energy description
of our model around the critical bifurcation point on one hand, and the
Ashkin-Teller model and a weakly dimerized XXZ spin-1/2 chain on the other. We
complement our field-theory understanding via tensor network simulations,
providing compelling quantitative evidences of all bosonization predictions.
Our findings are of interest to up-to-date cold atom experiments utilizing
Rydberg dressing, that have already demonstrated correlated ladder dynamics.
The scale (conformal) anomaly can generate an electric current near the
boundary of a system in the presence of a static magnetic field. The magnitude
of this magnetization current, produced at zero temperature and in the absence
of matter, is proportional to a beta function associated with the
renormalization of the electric charge. Using first-principle lattice
simulations, we investigate how the breaking of the scale symmetry affects this
``scale magnetic effect'' near a Dirichlet boundary in scalar QED (Abelian
Higgs model). We demonstrate the interplay of the generated current with vortex
excitations both in symmetric (normal) and broken (superconducting) phases and
compare the results with the anomalous current produced in the conformal,
scale-invariant regime. Possible experimental signatures of the effect in Dirac
semimetals are discussed.
Using numerically exact diagonalization, we study the correlated
Haldane-Hubbard model in the presence of dissipation. Such dissipation can be
modeled at short times by the dynamics governed by an effective non-Hermitian
Hamiltonian, of which we present a full characterization. If the dissipation
corresponds to a two-body loss, the repulsive interaction of the effective
Hamiltonian acquires an imaginary component. A competition between the
formation of a charge-ordered Mott insulator state and a topological insulator
ensues, but with the non-Hermitian contribution aiding in stabilizing the
topologically non-trivial regime, delaying the onset of the formation of a
local order parameter. Lastly, we analyze the robustness of the ordered phase
by following the full dissipative many-body real-time dynamics. An
exponentially fast melting of the charge order occurs, whose characteristic
rate is roughly independent of the interaction strength, for the case of
one-body dissipation.
Landau's quasiparticle formalism is generalized to describe a wide class of
strongly correlated Fermi systems, in addition to conventional Fermi liquids.
This class includes (i) so-called marginal exemplars and (ii) systems that
harbor interaction-driven flat bands, in both of which manifestations of
non-Fermi-liquid behavior are well documented. Specifically, the advent of such
flat bands is attributed to a spontaneous topological rearrangement of the
Landau state that supplements the conventional Landau quasiparticle picture
with a different set of quasiparticles, the so-called fermion condensate, whose
single-particle spectrum is dispersionless. The celebrated Landau-Luttinger
theorem is extended to marginal Fermi liquids, in which the density of the
augmented quasiparticle system is shown to coincide with the particle density.
On the other hand, the total density of a system hosting an interaction-driven
flat band turns out to be the sum of the densities of the two quasiparticle
subsystems: the Landau-like component and the fermion condensate. We
demonstrate that within the framework of the scenario proposed, salient
features of $D$-wave superconductivity of overdoped cuprates, including the
ratio $T_c^{\rm max}/T_F$ of the maximum critical temperature to the Fermi
temperature on the Uemura plot, are properly described.
We apply an Ising-type model to estimate the band gaps of the polytypes of
group IV elements (C, Si, and Ge) and binary compounds of groups: IV-IV (SiC,
GeC, and GeSi), and III-V (nitride, phosphide, and arsenide of B, Al, and Ga).
The models use reference band gaps of the simplest polytypes comprising 2--6
bilayers calculated with the hybrid density functional approximation, HSE06. We
report four models capable of estimating band gaps of nine polytypes containing
7 and 8 bilayers with an average error of $\lesssim0.05$ eV. We apply the best
model with an error of $<0.04$ eV to predict the band gaps of 497 polytypes
with up to 15 bilayers in the unit cell, providing a comprehensive view of the
variation in the electronic structure with the degree of hexagonality of the
crystal structure. Within our enumeration, we identify four rhombohedral
polytypes of SiC -- 9$R$, 12$R$, 15$R$(1), and 15$R$(2) -- and perform detailed
stability and band structure analysis. Of these, 15$R$(1) that has not been
experimentally characterized has the widest band gap ($>3.4$ eV); phonon
analysis and cohesive energy reveal 15$R$(1)-SiC to be metastable.
Additionally, we model the energies of valence and conduction bands of the
rhombohedral SiC phases at the high-symmetry points of the Brillouin zone and
predict band structure characteristics around the Fermi level. The models
presented in this study may aid in identifying polytypic phases suitable for
various applications, such as the design of wide-gap materials, that are
relevant to high-voltage applications. In particular, the method holds promise
for forecasting electronic properties of long-period and ultra-long-period
polytypes for which accurate first-principles modeling is computationally
challenging.
Magnetic multilayers with interlayer exchange coupling have been widely
studied for both static and dynamic regimes. Their dynamical responses depend
on the exchange coupling strength and magnetic properties of individual layers.
Magnetic resonance spectra in such systems are conveniently discussed in terms
of coupling of acoustic and optical modes. At a certain value of applied
magnetic field, the two modes come close to being degenerate and the spectral
gap indicates the strength of mode hybridisation. In this work, we
theoretically and experimentally study the mode hybridisation of
interlayer-exchange-coupled moments with dissimilar magnetisation and thickness
of two ferromagnetic layers. In agreement with symmetry analysis for
eigenmodes, our low-symmetry multilayers exhibit sizable spectral gaps for all
experimental conditions. The spectra agree well with the predictions from the
Landau-Lifshitz-Gilbert equation at the macrospin limit whose parameters are
independently fixed by static measurements.
The interplay between Coulomb interaction, electron-phonon coupling, and
phonon-phonon coupling has a significant impact on the low-energy behavior of
three-dimensional type-I tilted Dirac semimetals. To investigate this
phenomenon, we construct an effective theory, calculate one-loop corrections
contributed by all these interactions, and establish the coupled
energy-dependent flows of all associated interaction parameters by adopting the
renormalization group approach. Deciphering such coupled evolutions allows us
to determine a series of low-energy critical outcomes for these materials. At
first, we present the low-energy tendencies of all interaction parameters. The
tilting parameter exhibits distinct tendencies that depend heavily upon the
initial anisotropy of fermion velocities. In comparison, the latter is mainly
dominated by its own initial value but less sensitive to the former. With
variance of these two quantities, parts of the interaction parameters are
driven towards the strong anisotropy in the low-energy, indicating the screened
interaction in certain directions, while others tend to move towards an
approximate isotropy. Additionally, we observe that the tendencies of
interaction parameters can be qualitatively clustered into three distinct types
of fixed points, accompanying the potential instabilities around which certain
interaction-driven phase transition is trigged. Furthermore, approaching such
fixed points leads to physical quantities, such as the density of states,
compressibility, and specific heat, exhibiting behavior that is significantly
different from their non-interacting counterparts and even deviates slightly
from Fermi-liquid behavior. Our investigation sheds light on the intricate
relationship between different types of interactions in these semimetals, and
provide useful insights into their fundamental properties.
Floquet codes are a novel class of quantum error-correcting codes with
dynamically generated logical qubits, which arise from a periodic schedule of
non-commuting measurements. We engineer new examples of Floquet codes with
measurement schedules that $\textit{rewind}$ during each period. The rewinding
schedules are advantageous in our constructions for both obtaining a desired
set of instantaneous stabilizer groups and for constructing boundaries. Our
first example is a Floquet code that has instantaneous stabilizer groups that
are equivalent -- via finite-depth circuits -- to the 2D color code and
exhibits a $\mathbb{Z}_3$ automorphism of the logical operators. Our second
example is a Floquet code with instantaneous stabilizer codes that have the
same topological order as the 3D toric code. This Floquet code exhibits a
splitting of the topological order of the 3D toric code under the associated
sequence of measurements i.e., an instantaneous stabilizer group of a single
copy of 3D toric code in one round transforms into an instantaneous stabilizer
group of two copies of 3D toric codes up to nonlocal stabilizers, in the
following round. We further construct boundaries for this 3D code and argue
that stacking it with two copies of 3D subsystem toric code allows for a
transversal implementation of the logical non-Clifford $CCZ$ gate. We also show
that the coupled-layer construction of the X-cube Floquet code can be modified
by a rewinding schedule such that each of the instantaneous stabilizer codes is
finite-depth-equivalent to the X-cube model up to toric codes; the X-cube
Floquet code exhibits a splitting of the X-cube model into a copy of the X-cube
model and toric codes under the measurement sequence. Our final example is a
generalization of the honeycomb code to 3D, which has instantaneous stabilizer
codes with the same topological order as the 3D fermionic toric code.
The quest for room-temperature superconductors has been teasing scientists
and physicists, since its inception in 1911 itself. Several assertions have
already been made about room temperature superconductivity but were never
verified or reproduced across the labs. The cuprates were the earliest high
transition temperature superconductors, and it seems that copper has done the
magic once again. Last week, a Korean group synthesized a Lead Apatite-based
compound LK-99, showing a T$_c$ of above 400$^\circ$K. The signatures of
superconductivity in the compound are very promising, in terms of resistivity
(R = 0) and diamagnetism at T$_c$. Although, the heat capacity (C$_p$) did not
show the obvious transition at T$_c$. Inspired by the interesting claims of
above room temperature superconductivity in LK-99, in this article, we report
the synthesis of polycrystalline samples of LK-99, by following the same heat
treatment as reported in [1,2] by the two-step precursor method. The phase is
confirmed through X-ray diffraction (XRD) measurements, performed after each
heat treatment. The room temperature diamagnetism is not evidenced by the
levitation of a permanent magnet over the sample or vice versa. Further
measurements for the confirmation of bulk superconductivity on variously
synthesized samples are underway. Our results on the present LK-99 sample,
being synthesized at 925$^\circ$C, as of now do not approve the appearance of
bulk superconductivity at room temperature. Further studies with different heat
treatments are though, yet underway.
We examine the aggregation behavior of AuNPs of different sizes on graphene
as function of temperature using molecular dynamic simulations with Reax Force
Field (ReaxFF). In addition, the consequences of such aggregation on the
morphology of AuNPs and the charge transfer behavior of AuNP-Graphene hybrid
structure are analyzed. The aggregation of AuNPs on graphene is confirmed from
the center of mass distance calculation. The simulation results indicate that
the size of AuNPs and temperature significantly affect the aggregation behavior
of AuNPs on graphene. The strain calculation showed that shape of AuNPs changes
due to the aggregation and the smaller size AuNPs on graphene exhibit more
shape changes than larger AuNPs at all the temperatures studies in this work.
The charge transfer calculation reveals that, the magnitude of charge transfer
is higher for larger AuNPs-graphene composite when compared with smaller
AuNPs-graphene composite. The charge transfer trend and the trends seen in the
number of Au atoms directly in touch with graphene are identical. Hence, our
results conclude that, quantity of Au atoms directly in contact with graphene
during aggregation is primarily facilitates charge transfer between AuNPs and
graphene.
Recent reports of a possible room-temperature superconductor called LK-99
have generated a lot of attention worldwide. In just a few days, a large amount
of experimental works attempted to reproduce this sample and verify its
properties. At the same time a large amount of theoretical works have also been
reported. However, many experiments have drawn different conclusions, and many
theoretical results are not consistent with experimental results. For one of
the structures of LK-99 with the chemical formula as Pb9Cu(PO4)6O, many
first-principles calculations did not consider spin-orbit coupling and
concluded that it is a flat band metal. However, spin-orbit coupling is often
not negligible in systems with heavy elements, and LK-99 contains a large
amount of heavy element Pb. We performed calculations of electronic structure
of Pb9Cu(PO4)6O with spin-orbit coupling, and the results show that it's not a
metal but a semiconductor. This is consistent with many experimental results.
In the ferromagnetic state Pb9Cu(PO4)6O is an indirect-bandgap semiconductor
with a bandgap of 292 meV. Moreover, its conduction band is a flat band. At an
electron doping level of 0.5 e/unit cell, Pb9Cu(PO4)6O becomes metallic and has
a flat band with a width of only 25 meV at the Fermi level in the ferromagnetic
state. While in the antiferromagnetic-A state, Pb9Cu(PO4)6O is a direct-bandgap
semiconductor with a bandgap of 300 meV. As a magnetic narrowband
semiconductor, Pb9Cu(PO4)6O may have potential application value in the field
of optoelectronic device, photocatalytic, photodetector and spintronics device.
We derive Lorentz-invariant four-fermion interactions, including
Nambu-Jona-Lasinio type and superconducting type, which are widely studied in
high-energy physics, from the honeycomb lattice Hamiltonian with Hubbard
interaction. We investigate the phase transitions induced by these two
interactions and consider the effects of the chemical potential and magnetic
flux (Haldane mass term) on these phase transitions. We find that the
charge-density-wave and superconductivity generated by the attractive
interactions are mainly controlled by the chemical potential, while the
magnetic flux delimits the domain of phase transition. Our analysis underscores
the influence of the initial topological state on the phase transitions, a
facet largely overlooked in prior studies. We present experimental protocols
using cold atoms to verify our theoretical results.
Despite fascinating experimental results, the influence of defects and
elastic strains on the physical state of nanosized ferroelectrics is still
poorly explored theoretically. One of unresolved theoretical problems is the
analytical description of the strongly enhanced spontaneous polarization,
piezoelectric response, and dielectric properties of ferroelectric oxide thin
films and core-shell nanoparticles induced by elastic strains and stresses. In
particular, the 10-nm quasi-spherical BaTiO3 core-shell nanoparticles reveal a
giant spontaneous polarization up to 130 mu_C/cm2, where the physical origin is
a large Ti off-centering. The available theoretical description cannot explain
the giant spontaneous polarization observed in these spherical nanoparticles.
This work analyzes polar properties of BaTiO3 core-shell spherical
nanoparticles using the Landau-Ginzburg-Devonshire approach, which considers
the nonlinear electrostriction coupling and large Vegard strains in the shell.
We reveal that a spontaneous polarization greater than 50 mu_C/cm2 can be
stable in a (10-100) nm BaTiO3 core at room temperature, where a 5 nm
paraelectric shell is stretched by (3-6)% due to Vegard strains, which
contribute to the elastic mismatch at the core-shell interface. The
polarization value 50 mu_C/cm2 corresponds to high tetragonality ratios (1.02 -
1.04), which is further increased up to 100 mu_C/cm2 by higher Vegard strains
and/or intrinsic surface stresses leading to unphysically high tetragonality
ratios (1.08 - 1.16). The nonlinear electrostriction coupling and the elastic
mismatch at the core-shell interface are key physical factors of the
spontaneous polarization enhancement in the core. Doping with the
highly-polarized core-shell nanoparticles can be useful in optoelectronics and
nonlinear optics, electric field enhancement, reduced switching voltages,
catalysis, and electrocaloric nanocoolers.
Finding materials exhibiting superconductivity at room temperature has long
been one of the ultimate goals in physics and material science. Recently,
room-temperature superconducting properties have been claimed in a copper
substituted lead phosphate apatite (Pb$_{10-x}$Cu$_x$(PO$_4$)$_6$O, or called
LK-99) [1-3]. Using a similar approach, we have prepared LK-99 like samples and
confirmed the half-levitation behaviors in some small specimens under the
influence of a magnet at room temperature. To examine the magnetic properties
of our samples, we have performed systematic magnetization measurements on the
as-grown LK-99-like samples, including the half-levitated and non-levitated
samples. The magnetization measurements show the coexistence of
soft-ferromagnetic and diamagnetic signals in both half-levitated and
non-levitated samples. The electrical transport measurements on the as-grown
LK-99-like samples including both half-levitated and non-levitated samples show
an insulating behavior characterized by the increasing resistivity with the
decreasing temperature.
Ultracold Fermi gases of spin-3/2 atoms provide a clean platform to realise
SO(5) models of 4-Fermi interactions in the laboratory. By confining the atoms
in a two-dimensional Raman lattice, we show how this system can be used as a
flexible quantum simulator of Dirac quantum field theories (QFTs) that combine
Gross-Neveu and Thirring interactions with a higher-order topological twist. We
show that the lattice model corresponds to a regularization of this QFT with an
anisotropic twisted Wilson mass. This allows us to access higher-order
topological states protected by a hidden SO(5) symmetry, a remnant of the
original rotational symmetry of the 4-Fermi interactions that is not explicitly
broken by the lattice discretization. Using large-$N$ methods, we show that the
4-Fermi interactions lead to a rich phase diagram with various competing
fermion condensates. Our work opens a route for the implementation of
correlated higher-order topological states with tunable interactions that has
interesting connections to non-trivial relativistic QFTs of Dirac fermions in
$D = 2 + 1$ dimensions.

Date of feed: Tue, 29 Aug 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) **Nematic order in topological SYK models. (arXiv:2308.13601v1 [cond-mat.str-el])**

Andrew Hardy, Anjishnu Bose, Arun Paramekanti

**Network science Ising states of matter. (arXiv:2308.13604v1 [cond-mat.dis-nn])**

Hanlin Sun, Rajat Kumar Panda, Roberto Verdel, Alex Rodriguez, Marcello Dalmonte, Ginestra Bianconi

**Tuning the Curie temperature of a 2D magnet/topological insulator heterostructure to above room temperature by epitaxial growth. (arXiv:2308.13620v1 [cond-mat.mtrl-sci])**

Wenyi Zhou, Alexander J. Bishop, Xiyue S. Zhang, Katherine Robinson, Igor Lyalin, Ziling Li, Ryan Bailey-Crandell, Thow Min Jerald Cham, Shuyu Cheng, Yunqiu Kelly Luo, Daniel C. Ralph, David A. Muller, Roland K. Kawakami

**Strain Engineering for High-Performance Phase Change Memristors. (arXiv:2308.13637v1 [physics.app-ph])**

Wenhui Hou, Ahmad Azizimanesh, Aditya Dey, Yufeng Yang, Wuxiucheng Wang, Chen Shao, Hui Wu, Hesam Askari, Sobhit Singh, Stephen M. Wu

**Conservation laws for interacting magnetic nanoparticles at finite temperature. (arXiv:2308.13683v1 [cond-mat.mes-hall])**

Frederik L. Durhuus, Marco Beleggia, Cathrine Frandsen

**The Search for Stable Graphene Defect Structures: Optimized Molecular Dynamics Simulations and Energetics of 55-77 Stone-Wales defects. (arXiv:2308.13810v1 [cond-mat.mtrl-sci])**

Ji Wei Yoon

**Topological superconductivity from first-principles I: Shiba band structure and topological edge states of artificial spin chains. (arXiv:2308.13824v1 [cond-mat.supr-con])**

Bendegúz Nyári, András Lászlóffy, Gábor Csire, László Szunyogh, Balázs Újfalussy

**Magnetism and berry phase manipulation in an emergent structure of perovskite ruthenate by (111) strain engineering. (arXiv:2308.13825v1 [cond-mat.str-el])**

Zhaoqing Ding, Xuejiao Chen, Zhenzhen Wang, Qinghua Zhang, Fang Yang, Jiachang Bi, Ting Lin, Zhen Wang, Xiaofeng Wu, Minghui Gu, Meng Meng, Yanwei Cao, Lin Gu, Jiandi Zhang, Zhicheng Zhong, Xiaoran Liu, Jiandong Guo

**Topological superconductivity from first-principles II: Effects from manipulation of spin spirals $-$ Topological fragmentation, braiding, and Quasi-Majorana Bound States. (arXiv:2308.13831v1 [cond-mat.supr-con])**

András Lászlóffy, Bendegúz Nyári, Gábor Csire, László Szunyogh, Balázs Újfalussy

**Ab initio Investigations on the Electronic Properties and Stability of Cu-Substituted Lead Apatite (LK-99) family with different doping concentrations (x=0, 1, 2). (arXiv:2308.13938v1 [cond-mat.mtrl-sci])**

Songge Yang, Guangchen Liu, Yu Zhong

**Indication of novel magnetoresistance mechanism in (Bi,Sb)$_2$(Te,Se)$_3$ 3D topological insulator thin films. (arXiv:2308.14008v1 [cond-mat.mes-hall])**

N.P. Stepina, A.O. Bazhenov, A.V. Shumilin, A.Yu. Kuntsevich, V.V. Kirienko, E.S. Zhdanov, D.V. Ishchenko, O.E. Tereshchenko

**Reconstruction changes drive surface diffusion and determine the flatness of oxide surfaces. (arXiv:2308.14043v1 [cond-mat.mtrl-sci])**

Giada Franceschi, Michael Schmid, Ulrike Diebold, Michele Riva

**One-Half Topological Number in Entangled Quantum Physics. (arXiv:2308.14062v1 [cond-mat.mes-hall])**

Karyn Le Hur

**Sampling with flows, diffusion and autoregressive neural networks: A spin-glass perspective. (arXiv:2308.14085v1 [cond-mat.dis-nn])**

Davide Ghio, Yatin Dandi, Florent Krzakala, Lenka Zdeborová

**Persistence of Monoclinic Crystal Structure in Three-Dimensional Second-Order Topological Insulator Candidate 1T'-MoTe2 Thin Flake without Structural Phase transition. (arXiv:2308.14125v1 [cond-mat.mtrl-sci])**

Bo Su, Yuan Huang, Yan Hui Hou, Jiawei Li, Rong Yang, Yongchang Ma, Yang Yang, Guangyu Zhang, Xingjiang Zhou, Jianlin Luo, Zhi-Guo Chen

**Topology and dynamics of higher-order multiplex networks. (arXiv:2308.14189v1 [nlin.AO])**

Sanjukta Krishnagopal, Ginestra Bianconi

**Discovery of a Bloch point quadrupole constituting hybrid topological strings. (arXiv:2308.14219v1 [cond-mat.str-el])**

Fehmi Sami Yasin (1), Jan Masell (1 and 2), Yoshio Takahashi (3), Tetsuya Akashi (3), Norio Baba (4), Kosuke Karube (1), Daisuke Shindo (1), Takahisa Arima (1 and 5), Yasujiro Taguchi (1), Yoshinori Tokura (1 and 6 and 7), Toshiaki Tanigaki (3), Xiuzhen Yu (1) ((1) RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan, (2) Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany, (3) Research and Development Group, Hitachi Ltd., Hatoyama, Japan, (4) Research Institute for Science and Technology, Kogakuin University, Hachioji, Japan, (5) Department of Advanced Materials Science, University of Tokyo, Kashiwa, Japan, (6) Department of Applied Physics, University of Tokyo, Tokyo, Japan, (7) Tokyo College, University of Tokyo, Tokyo, Japan)

**The Replica Symmetry Broken States of some Glass Models. (arXiv:2308.14229v1 [cond-mat.dis-nn])**

J. Yeo, M. A. Moore

**Three-dimensional flat Landau levels in an inhomogeneous acoustic crystal. (arXiv:2308.14313v1 [cond-mat.mes-hall])**

Zheyu Cheng, Yi-jun Guan, Haoran Xue, Yong Ge, Ding Jia, Yang Long, Shou-qi Yuan, Hong-xiang Sun, Yidong Chong, Baile Zhang

**Spin-polarized transport properties in magnetic moir\'e superlattices. (arXiv:2308.14342v1 [cond-mat.mes-hall])**

Zhao Gong, Qing-Qing Zhang, Hui-Ying Mu, Xing-Tao An, Jian-Jun Liu

**Anisotropic and pressure tunable magnetism of titanium-based Kagome ferromagnet SmTi3Bi4. (arXiv:2308.14349v1 [cond-mat.mtrl-sci])**

Long Chen, Ying Zhou, He Zhang, Zhongnan Guo, Xiaohui Yu, Gang Wang

**Exciton-exciton Interaction in Monolayer MoSe$_2$ from Mutual Screening of Coulomb Binding. (arXiv:2308.14362v1 [cond-mat.mtrl-sci])**

Ke Xiao, Tengfei Yan, Chengxin Xiao, Feng-ren Fan, Ruihuan Duan, Zheng Liu, Kenji Watanabe, Takashi Taniguchi, Wang Yao, Xiaodong Cui

**Abnormal behavior of preferred formation of cationic vacancy from the interior in {\gamma}-GeSe monolayer with the stereo-chemical antibonding lone-pair state. (arXiv:2308.14413v1 [cond-mat.mtrl-sci])**

Changmeng Huan, Yongqing Cai, Devesh R. Kripalani, Kun Zhou, Qingqing Ke

**High-throughput screening of heterogeneous transition metal dual-atom catalysts by synergistic effect for nitrate reduction to ammonia. (arXiv:2308.14439v1 [cond-mat.mtrl-sci])**

Zheng Shu, Hongfei Chen, Xing Liu, Huaxian Jia, Hejin Yan, Yongqing Cai

**Magnetic kagome materials RETi3Bi4 family with weak interlayer interactions. (arXiv:2308.14509v1 [cond-mat.mtrl-sci])**

Jingwen Guo, Liqin Zhou, Jianyang Ding, Gexing Qu, Zhengtai Liu, Yu Du, Heng Zhang, Jiajun Li, Yiying Zhang, Fuwei Zhou, Wuyi Qi, Fengyi Guo, Tianqi Wang, Fucong Fei, Yaobo Huang, Tian Qian, Dawei Shen, Hongming Weng, Fengqi Song

**Topological marker approach to an interacting Su-Schrieffer-Heeger model. (arXiv:2308.14534v1 [cond-mat.str-el])**

Pedro B. Melo, Sebastião A. S. Júnior, Wei Chen, Rubem Mondaini, Thereza Paiva

**External magnetic fields enhance capture of magnetic nanoparticles flowing through molded microfluidic channels by ferromagnetic nanostructures. (arXiv:2308.14543v1 [cond-mat.mes-hall])**

Reyne Dowling, Mikhail Kostylev

**Two-dimensional weak topological insulators and superconductors. (arXiv:2308.14564v1 [cond-mat.mes-hall])**

Yuanjun Jin, XingYu Yue, Yong Xu, Xiang-Long Yu, Guoqing Chang

**Impact of atomic reconstruction on optical spectra of twisted TMD homobilayers. (arXiv:2308.14633v1 [cond-mat.mes-hall])**

Joakim Hagel, Samuel Brem, Johannes Abelardo Pineiro, Ermin Malic

**New polarization rotation and exact TEM wave solutions in topological insulators. (arXiv:2308.14673v1 [cond-mat.mes-hall])**

Sebastián Filipini, Mauro Cambiaso

**Enhanced quantum transport in chiral quantum walks. (arXiv:2308.14747v1 [quant-ph])**

Emilio Annoni, Massimo Frigerio, Matteo G. A. Paris

**Ultrahigh Photoresponsivity of Gold Nanodisk Array/CVD MoS$_2$-based Hybrid Phototransistor. (arXiv:2308.14750v1 [cond-mat.mtrl-sci])**

Shyam Narayan Singh Yadav, Po-Liang Chen, Yu-Chi Yao, Yen-Yu Wang, Der-Hsien Lien, Yu-Jung Lu, Ya-Ping Hsieh, Chang-Hua Liu, Ta-Jen Yen

**Impact of the X ray edge singularity on detection of relic neutrinos in the PTOLEMY project. (arXiv:2202.07406v2 [physics.ins-det] UPDATED)**

Zhiyang Tan, Vadim Cheianov

**Charge density wave and superconductivity in 6R-TaS2. (arXiv:2206.00281v3 [cond-mat.supr-con] UPDATED)**

Sudip Pal, Prakash Bahera, S. R. Sahoo, Himanshu Srivastava, A. K. Srivastava, N. P. Lalla, Raman Sankar, A. Banerjee, S. B. Roy

**Extremely Large Magnetoresistance and Anisotropic Transport in Multipolar Kondo System PrTi$_{2}$Al$_{20}$. (arXiv:2210.12436v2 [cond-mat.str-el] UPDATED)**

Takachika Isomae, Akito Sakai, Mingxuan Fu, Takanori Taniguchi, Masashi Takigawa, Satoru Nakatsuji

**Observation of suppressed viscosity in the normal state of $^3$He due to superfluid fluctuations. (arXiv:2212.12520v3 [cond-mat.supr-con] UPDATED)**

Rakin N. Baten, Yefan Tian, Eric N. Smith, Erich Mueller, Jeevak M. Parpia

**Resonating holes vs molecular spin-orbit coupled states in group-5 lacunar spinels. (arXiv:2301.03392v3 [cond-mat.str-el] UPDATED)**

Thorben Petersen, Pritam Bhattacharyya, Ulrich K. Rößler, Liviu Hozoi

**Heavy quasiparticles and cascades without symmetry breaking in twisted bilayer graphene. (arXiv:2301.13024v3 [cond-mat.str-el] UPDATED)**

Anushree Datta, M.J. Calderón, A. Camjayi, E. Bascones

**GlassNet: a multitask deep neural network for predicting many glass properties. (arXiv:2303.15538v2 [cond-mat.soft] UPDATED)**

Daniel R. Cassar

**Preparing and Analyzing Solitons in the sine-Gordon Model with Quantum Gas Microscopes. (arXiv:2303.16221v2 [cond-mat.quant-gas] UPDATED)**

Elisabeth Wybo, Alvise Bastianello, Monika Aidelsburger, Immanuel Bloch, Michael Knap

**Higher-order topological and nodal superconducting transition-metal sulfides MS (M = Nb and Ta). (arXiv:2304.03062v4 [cond-mat.supr-con] UPDATED)**

Yipeng An, Juncai Chen, Yong Yan, Jinfeng Wang, Yinong Zhou, Zhengxuan Wang, Chunlan Ma, Tianxing Wang, Ruqian Wu, Wuming Liu

**Magnetic properties of a spin-orbit entangled Jeff=1/2 three-dimensional frustrated rare-earth hyperkagome. (arXiv:2304.07350v2 [cond-mat.str-el] UPDATED)**

B. Sana, M. Barik, M. Pregelj, U. Jena, M. Baenitz, J. Sichelschmidt, K. Sethupathi, P. Khuntia

**Ab-initio Simulations of Coherent Phonon-Induced Pumping of Carriers in Zirconium Pentatelluride. (arXiv:2304.08449v2 [cond-mat.mtrl-sci] UPDATED)**

Tao Jiang, Peter P. Orth, Liang Luo, Lin-Lin Wang, Feng Zhang, Cai-Zhuang Wang, Jin Zhao, Kai-Ming Ho, Jigang Wang, Yong-Xin Yao

**Topological properties and shape of proliferative and non-proliferative cell monolayers. (arXiv:2305.03990v2 [cond-mat.soft] UPDATED)**

Daria S. Roshal, Karim Azzag, Kirill K. Fedorenko, Sergei B. Rochal, Stephen Baghdiguian

**Emergence of non-Abelian SU(2) invariance in Abelian frustrated fermionic ladders. (arXiv:2305.06911v2 [cond-mat.str-el] UPDATED)**

Bachana Beradze, Mikheil Tsitsishvili, Emanuele Tirrito, Marcello Dalmonte, Titas Chanda, Alexander Nersesyan

**Generation of electric current by magnetic field at the boundary: quantum scale anomaly vs. semiclassical Meissner current outside of the conformal limit. (arXiv:2305.14033v2 [hep-lat] UPDATED)**

M. N. Chernodub, V. A. Goy, A. V. Molochkov

**Non-Hermitian Haldane-Hubbard model: Effective description of one- and two-body dissipation. (arXiv:2305.18762v2 [cond-mat.str-el] UPDATED)**

Can Wang, Tian-Cheng Yi, Jian Li, Rubem Mondaini

**A unified quasiparticle approach to the theory of strongly correlated electron liquids. (arXiv:2305.19385v3 [cond-mat.str-el] UPDATED)**

V. A. Khodel, J. W. Clark, M. V. Zverev

**Band gaps of long-period polytypes of IV, IV-IV, and III-V semiconductors estimated with an Ising-type additivity model. (arXiv:2306.17756v3 [physics.chem-ph] UPDATED)**

Raghunathan Ramakrishnan, Shruti Jain

**Magnon-magnon coupling in synthetic ferrimagnets. (arXiv:2307.06888v2 [cond-mat.mtrl-sci] UPDATED)**

A. Sud, K. Yamamoto, K. Z. Suzuki, S. Mizukami, H. Kurebayashi

**Critical fates induced by interaction competition in the three-dimensional tilted Dirac semimetals. (arXiv:2307.13436v2 [cond-mat.str-el] UPDATED)**

Jing Wang, Jie-Qiong Li, Wen-Hao Bian, Qiao-Chu Zhang, Xiao-Yue Ren

**Engineering Floquet codes by rewinding. (arXiv:2307.13668v3 [quant-ph] UPDATED)**

Arpit Dua, Nathanan Tantivasadakarn, Joseph Sullivan, Tyler D. Ellison

**Synthesis of possible room temperature superconductor LK-99:Pb$_9$Cu(PO$_4$)$_6$O. (arXiv:2307.16402v2 [cond-mat.supr-con] UPDATED)**

Kapil Kumar, N.K. Karn, V.P.S. Awana (CSIR-NPL, INDIA)

**Gold Nanoparticles Aggregation on Graphene Using Reactive Force Field: A Molecular Dynamic Study. (arXiv:2308.04089v3 [physics.app-ph] UPDATED)**

J. Hingies Monisha, V. Vasumathi, Prabal K Maiti

**Magnetic Properties and Spin-orbit Coupling induced Semiconductivity in LK-99. (arXiv:2308.05134v2 [cond-mat.supr-con] UPDATED)**

Hua Bai, Lei Gao, Jianrong Ye, Chunhua Zeng, Wuming Liu

**Lorentz-Invariant Interactions in Honeycomb Lattice with Hubbard Interaction. (arXiv:2308.10863v2 [cond-mat.str-el] UPDATED)**

Qiao Yang, Yu-Biao Wu, Lin Zhuang, Ji-Min Zhao, Wu-Ming Liu

**Strain-Induced Polarization Enhancement in BaTiO$_3$ Core-Shell Nanoparticles. (arXiv:2308.11044v2 [cond-mat.mtrl-sci] UPDATED)**

Eugene A. Eliseev, Anna N. Morozovska, Sergei V. Kalinin, Dean R. Evans

**Ferromagnetic and insulating behavior in both half magnetic levitation and non-levitation LK-99 like samples. (arXiv:2308.11768v2 [cond-mat.supr-con] UPDATED)**

Pinyuan Wang, Xiaoqi Liu, Jun Ge, Chengcheng Ji, Haoran Ji, Yanzhao Liu, Yiwen Ai, Gaoxing Ma, Shichao Qi, Jian Wang

**A higher-order topological twist on cold-atom SO(5) Dirac fields. (arXiv:2308.12051v2 [cond-mat.quant-gas] UPDATED)**

A. Bermudez, D. González-Cuadra, S. Hands

Found 4 papers in prb

Date of feed: Tue, 29 Aug 2023 03:17:05 GMT**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **Erratum: Effects of spin-orbit interaction and electron correlations in strontium titanate [Phys. Rev. B 106, 224519 (2022)]**

Sergei Urazhdin, Ekram Towsif, and Alexander Mitrofanov

Author(s): Sergei Urazhdin, Ekram Towsif, and Alexander Mitrofanov

[Phys. Rev. B 108, 059902] Published Mon Aug 28, 2023

The material class of kagome metals has rapidly grown and has been established as a field to explore the interplay between electronic topology and magnetism. In this work, we report a combined theoretical and experimental study of the anomalous Hall effect of the ferromagnetic kagome metal ${\mathrm… [Phys. Rev. B 108, 075164] Published Mon Aug 28, 2023 |

We calculate optical conductivity for bilayer dice lattices in commensurate vertically aligned stackings. The interband optical conductivity reveals a rich activation behavior unique for each of the four stackings. We found that the intermediate energy band, which corresponds to the flat band of a s… [Phys. Rev. B 108, 075167] Published Mon Aug 28, 2023 |

We consider electron-hole Cooper pair condensation in a heterostructure formed by a topological insulator (TI) film and a quantum well. We argue that the helical nature of the Dirac electronic states at the TI surface results in the presence of two competing degenerate pairing channels. The correspo… [Phys. Rev. B 108, 075433] Published Mon Aug 28, 2023 |

Found 1 papers in nano-lett

Date of feed: Mon, 28 Aug 2023 13:14:23 GMT**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+)|(flatband)|(flat.{1}band)|(LK.{1}99) **[ASAP] Observation of Termination-Dependent Topological Connectivity in a Magnetic Weyl Kagome Lattice**

Federico Mazzola, Stefan Enzner, Philipp Eck, Chiara Bigi, Matteo Jugovac, Iulia Cojocariu, Vitaliy Feyer, Zhixue Shu, Gian Marco Pierantozzi, Alessandro De Vita, Pietro Carrara, Jun Fujii, Phil D. C. King, Giovanni Vinai, Pasquale Orgiani, Cephise Cacho, Matthew D. Watson, Giorgio Rossi, Ivana Vobornik, Tai Kong, Domenico Di Sante, Giorgio Sangiovanni, and Giancarlo PanaccioneNano LettersDOI: 10.1021/acs.nanolett.3c02022