Found 47 papers in cond-mat Graphene nanoribbons (GNRs) are atomically precise stripes of graphene with
tunable electronic properties, making them promising for room-temperature
switching applications like field-effect transistors (FETs). However,
challenges persist in GNR processing and characterization, particularly
regarding GNR alignment during device integration. In this study, we
quantitatively assess the alignment and quality of 9-atom-wide armchair
graphene nanoribbons (9-AGNRs) on different substrates using polarized Raman
spectroscopy. Our approach incorporates an extended model that describes GNR
alignment through a Gaussian distribution of angles. We not only extract the
angular distribution of GNRs but also analyze polarization-independent
intensity contributions to the Raman signal, providing insights into surface
disorder on the growth substrate and after substrate transfer. Our findings
reveal that low-coverage samples grown on Au(788) exhibit superior uniaxial
alignment compared to high-coverage samples, attributed to preferential growth
along step edges, as confirmed by scanning tunneling microscopy (STM). Upon
substrate transfer, the alignment of low-coverage samples deteriorates,
accompanied by increased surface disorder. On the other hand, high-coverage
samples maintain alignment and exhibit reduced disorder on the target
substrate. Our extended model enables a quantitative description of GNR
alignment and quality, facilitating the development of GNR-based nanoelectronic
devices.
Twisting is a novel technique for creating strongly correlated effects in
two-dimensional bilayered materials, and can tunably generate nontrivial
topological properties, magnetism, and superconductivity. Magnetism is
particularly significant as it can both compete with superconductivity and lead
to the emergence of nontrivial topological states. However, the origin of
magnetism in twisted structures remains a subject of controversy. Using
self-developed large-scale electronic structure calculations, we propose the
magnetism in these twisted bilayer systems originates from spin splitting
induced by the enhanced ratio of the exchange interaction to band dispersion.
We classify different ways to passively protect classical and quantum
information, i.e. we do not allow for syndrome measurements, in the context of
local Lindblad models for spin systems. Within this family of models, we
suggest that passive error correction is associated with nontrivial phases of
matter and propose a definition for dissipative phases based on robust steady
state degeneracy of a Lindbladian in the thermodynamic limit. We study three
thermalizing models in this context: the 2D Ising model, the 2D toric code, and
the 4D toric code. In the low-temperature phase, the 2D Ising model hosts a
robust classical steady state degeneracy while the 4D toric code hosts a robust
quantum steady state degeneracy. We perturb the models with terms that violate
detailed balance and observe that qualitative features remain unchanged,
suggesting that $\mathbb{Z}_2$ symmetry breaking in a Lindbladian is useful to
protect a classical bit while intrinsic topological order protects a qubit.
We propose a novel mechanism of impurity screening in (1+1)$d$ quantum
critical states described by conformal field theories (CFTs). An impurity can
be screened if it has the same quantum numbers as some gapless degrees of
freedom of the CFT. The common source of these degrees of freedom is the chiral
primary fields of the CFT, but we uncover that topological defect lines of the
CFT may also take this role. Theoretical analysis relies on the insight that
the impurities can be interpreted as edge modes of certain symmetry-protected
topological (SPT) states. By stacking a SPT state with a CFT, one or two
interfaces on which the SPT edge modes reside are created. If screening occurs
due to topological defect lines, a symmetry-enriched CFT with exotic boundary
states are obtained. The boundary conditions that appear in these cases are
difficult to achieve using previously known methods. Numerical simulations are
performed in two quantum spin chains whose bulks are described by the
SU(3)$_{1}$ and Spin(5)$_{1}$ CFTs and edges are coupled to spin-1/2
impurities. In both cases, low-energy eigenvalues are consistent with
analytical predictions.
Skyrmion bags are composed of an outer skyrmion and arbitrary inner
skyrmions, which have recently been observed in bulk chiral magnets, but still
remain elusive in magnetic films. Here, we propose a method of creating
skyrmion bags in a thin-film nanodisk, which includes three steps. Firstly, the
size of outer skyrmion is enlarged by a vertical magnetic field, then inner
skyrmions are nucleated at an off-center area by local current injection, and
the system is finally reconstructed due to multiple inter-skyrmion potentials.
Thus, skyrmion bags with topological charge up to forty can be created.
Simulated Lorentz transmission electron microscopy images are given to
facilitate the experimental demonstration. Our proposal is expected to inspire
relevant experiments in magnetic films, and pave the way for potential
spintronic applications based on skyrmion bags.
Measurements of magnetic properties at the atomic scale require probes
capable of combining high spatial resolution with spin sensitivity.
Spin-polarized scanning tunneling microscopy (SP-STM) fulfills these conditions
by using atomically sharp magnetic tips. The imaging of spin structures results
from the tunneling magneto-conductance that depends on the imbalance in the
local density of spin-up and spin-down electrons. Spin-sensitive tips are
generally formed from bulk materials or by coating non-magnetic tips with a
thin magnetic layer. However, ferromagnetic materials generate stray magnetic
fields which can influence the magnetic structure of the probed system, while
the magnetization of antiferromagnetic materials is difficult to set tip by
externally applied magnetic fields. Here, we use functionalized
Yu-Shiba-Rusinov (YSR) tips prepared by attaching magnetic adatoms at the apex
of a superconducting cluster to image magnetic interactions at the atomic
scale. We demonstrate that YSR tips are capable of sensing different
magnetization directions, conferring them full magnetic sensitivity. We
additionally show that the finite size of the tip superconducting cluster makes
it robust against relatively strong magnetic fields, making YSR tips capable of
visualizing magnetic field driven transitions of the spin texture.
We consider a chain consisting of $n+1$ pinned harmonic oscillators subjected
on the right to a time dependent periodic force $\cF(t)$ while Langevin
thermostats are attached at both endpoints of the chain. We show that for long
times the system is described by a Gaussian measure whose covariance function
is independent of the force, while the means are periodic. We compute
explicitly the work and energy due to the periodic force for all $n$ including
$n\to\infty$.
We explore from first-principles calculations the ferroelectric material
Pb5Ge3O11 as a model for controlling the spin-orbit interaction (SOC) in
crystalline solids. The SOC has a surprisingly strong effect on the structural
energy landscape by deepening the ferroelectric double well. We observe that
this effect comes from a specific Pb Wyckoff site that lies on the verge of a
natural cavity channel of the crystal. We also find that a unique cavity state
is formed by the empty 6p states of another Pb site at the edge of the cavity
channel. This cavity state exhibits a sizeable spin splitting with a mixed
Rashba-Weyl character and a topologically protected crossing of the related
bands. We also show that the ferroelectric properties and the significant SOC
effects are exceptionally robust against n-doping up to several electrons per
unit cell. We trace the provenance of these original effects to the unique
combination of the structural cavity channel and the chemistry of the Pb atoms
with 6p orbitals localizing inside the channel.
We investigate the mesoscopic transport through a twisted bilayer graphene
(TBG) consisting of a clean graphene nanoribbon on the bottom and a disordered
graphene disc on the top. We show that, with strong top-layer disorder the
transmission through such a device shows a sequence of resonant peaks with
respect to the rotation angle $\theta$, where at the resonance angles
$\theta_c$ the disc region contains one giant hexagonal moir{\'e} supercell. A
further investigation shows that the value of $\theta_c$ shows negligible
dependence on the disorder strength, the Fermi energy, and the shape
distortion, indicating the resonance is a robust geometric feature of the
moir{\'e} supercell. We explain this geometric resonance based on the bound
states formed inside the moir{\'e} supercell, with their averaged local density
of states dominating at the AA stacking region while minimizing at the AB
stacking region. By increasing the interlayer distance, the peak becomes less
pronounced which further confirms the role of interlayer coupling. The results
presented here suggest a new mechanism to tune the quantum transport signal
through the twist angle in disordered moir{\'e} systems.
The anomalous Hall effect has considerable impact on the progress of
condensed matter physics and occurs in systems with time-reversal symmetry
breaking. Here we theoretically investigate the anomalous Hall effect in
nonmagnetic transition-metal pentatelluride $\mathrm{ZrTe_{5}}$ and
$\mathrm{HfTe}_{5}$. In the presence of Zeeman splitting and Dirac mass, there
is an intrinsic anomalous Hall conductivity induced by the Berry curvature in
the semiclassical treatment. In a finite magnetic field, the anomalous Hall
conductivity rapidly decays to zero for constant spin-splitting and vanishes
for the magnetic-field-dependent Zeeman energy. A semiclassical formula is
derived to depict the magnetic field dependence of the Hall conductivity, which
is beneficial for experimental data analysis. Lastly, when the chemical
potential is fixed in the magnetic field, a Hall conductivity plateau arises,
which may account for the observed anomalous Hall effect in experiments.
Non-Abelian phenomena and non-Hermitian systems have both been widely
explored in recent years. As a bridge between the two, we introduce and develop
non-Abelian gauge engineering for realizing multi-fold spectral topology. As an
example of our proposal, we engineer non-Hermiticity in the paradigmatic
Su-Schrieffer-Heeger (SSH) model by introducing a generalized non-Abelian
gauge, leading to an emergent two-fold spectral topology that governs the
decoupled behaviour of the corresponding non-Hermitian skin effect. As a
consequence of the non-Abelian gauge choice, our model exhibits a rich phase
diagram consisting of distinct topological phases, which we characterize by
introducing the notion of paired winding numbers, which, in turn, predict the
direction of skin localization under open boundaries. We demonstrate that the
choice of gauge parameters enables control over the directionality of the skin
effect, allowing for it to be unilateral or bilateral. Furthermore, we discover
non-dispersive flat bands emerging within the inherent SSH model framework,
arising from the non-Abelian gauge. We also introduce a simplified toy model to
capture the underlying physics, thereby giving direct physical insights. Our
findings pave way for the exploration of unconventional spectral topology
through non-Abelian gauges.
We identify the triple-Q (3Q) state as magnetic ground state in Pd/Mn and
Rh/Mn bilayers on Re(0001) using spin-polarized scanning tunneling microscopy
and density functional theory. An atomistic model reveals that in general the
3Q state with tetrahedral magnetic order and zero net spin moment is coupled to
a hexagonal atomic lattice in a highly symmetric orientation via the
anisotropic symmetric exchange interaction, whereas other spin-orbit coupling
terms cancel due to symmetry. Our experiments are in agreement with the
predicted orientation of the 3Q state. A distortion from the ideal tetrahedral
angles leads to other orientations of the 3Q state which, however, results in a
reduced topological orbital magnetization compared to the ideal 3Q state.
We report a comprehensive study of magneto-transport properties in MoSi2 bulk
and thin films. Textured MoSi2 thin films of around 70 nm were deposited on
silicon substrates with different orientations. Giant magnetoresistance of
1000% was observed in sintered bulk samples while MoSi2 single crystals exhibit
a magnetoresistance (MR) value of 800% at low temperatures. At the low
temperatures, the MR of the textured thin films show weak anti-localization
behaviour owing to the spin orbit coupling effects. Our first principle
calculation show the presence of surface states in this material. The
resistivity of all the MoSi2 thin films is significantly low and nearly
independent of the temperature, which is important for electronic devices.
We study the Andreev reflections and the quantum transport in the
proximitized graphene/superconductor junction. The proximitized graphene
possesses the pseudospin staggered potential and the intrinsic spin-orbit
coupling induced by substrate, which are responsible for the spin-valley
dependent double Andreev reflections and the anomalous transport properties in
the junction. The pure specular Andreev reflection can happen in the
superconducting gap for the $K\uparrow$ and $K'\downarrow$ electrons while the
pure retro-Andreev reflection happens for the $K\downarrow$ and $K'\uparrow$
electrons. The coexisting two types of Andreev reflections related to the fixed
spin-valley indices strongly depend on the chemical potential of the
proximitized graphene. The condition of the emergence of the specific type of
Andreev reflection for the electrons with the fixed spin-valley index is
clarified. The spin-valley dependent Andreev reflections bring about the
peculiar conductance spectra of the junction, which can help determine the
values of the pseudospin staggered potential and the intrinsic spin-orbit
coupling induced in graphene. Hence, our research results not only provide an
experimental method to detect the induced potential and coupling in graphene
but also establish the foundation of the superconductor electronics based on
the spin-valley indices.
We study quantum many-body systems in the presence of an exotic antiunitary
translation or inversion symmetry involving time reversal. Based on a
symmetry-twisting method and spectrum robustness,we propose that a half-integer
spin chain which respects any of these two antiunitary crystalline symmetries
in addition to the discrete $\mathbb{Z}_2\times\mathbb{Z}_2$ global
spin-rotation symmetry must either be gapless or possess degenerate ground
states. This explains the gaplessness of a class of chiral spin models not
indicated by the Lieb-Schultz-Mattis (LSM) theorem and its known extensions.
Moreover, we present symmetry classes with minimal sets of generators that give
nontrivial LSM-type constraints, argued by the bulk-boundary correspondence in
2d symmetry-protected topological phases as well as lattice homotopy. Our
results for detecting the ingappability of 1d quantum magnets from the
interplay between spin-rotation symmetries and magnetic space groups are
applicable to systems with a broader class of spin interactions, including the
Dzyaloshinskii-Moriya and triple-product interactions.
We extend the notion of topologically protected semi-metallic band crossings
to hyperbolic lattices in negatively curved space. Due to their distinct
translation group structure, such lattices support non-Abelian Bloch states
which, unlike conventional Bloch states, acquire a matrix-valued Bloch factor
under lattice translations. Combining diverse numerical and analytical
approaches, we uncover a quartic scaling in the density of states at low
energies, and illuminate a nodal manifold of codimension five in the reciprocal
space. The nodal manifold is topologically protected by a non-zero second Chern
number, reminiscent of the characterization of Weyl nodes by the first Chern
number.
Two theorems on electron states in helimagnets are proved. They reveal a
Kramers-like degeneracy in helical magnetic field. Since a commensurate helical
magnetic system is transitionally invariant with two multiple periods (ordinary
translations and generalized ones with rotations), the band structure turns out
to be topologically nontrivial. Together with the degeneracy, this gives an
unusual spin structure of electron bands. A 2D model of nearly free electrons
is proposed to describe conductive hexagonal palladium layers under an
effective field of magnetically ordered CrO$_2$ spacers in PdCrO$_2$. The spin
texture of the Fermi surface leads to abnormal conductivity.
We propose how to create, control, and read-out real-space localized spin
qubits in proximitized finite graphene nanoribbon (GNR) systems using purely
electrical methods. Our proposed nano-qubits are formed of in-gap
singlet-triplet states that emerge through the interplay of Coulomb and
relativistic spin-dependent interactions in GNRs placed on a magnetic
substrate. Application of an electric field perpendicular to the GNR
heterostructure leads to a sudden change in the proximity couplings, i.e. a
quantum quench, which enables us to deterministically rotate the nano-qubit to
any arbitrary point on the Bloch sphere. We predict these spin qubits to
undergo Rabi oscillations with optimal visibility and frequencies in excess of
10 GHz. Our findings open up a new avenue for the realization of graphene-based
quantum computing with ultra-fast all-electrical methods.
Phenalenyl is a radical nanographene with triangular shape that hosts an
unpaired electron with spin S = 1/2. The open-shell nature of phenalenyl is
expected to be retained in covalently bonded networks. Here, we study a first
step in that direction and report the synthesis of the phenalenyl dimer by
combining in-solution synthesis and on-surface activation and its
characterization both on Au(111) and on a monolayer of NaCl on top of Au(111)
by means of inelastic electron tunneling spectroscopy (IETS). IETS shows
inelastic steps that, together with a thorough theoretical analysis, are
identified as the singlet-triplet excitation arising from interphenalenyl
exchange. Two prominent features of our data permit to shed light on the nature
of spin interactions in this system. First, the excitation energies with and
without the NaCl decoupling layer are 48 and 41 meV, respectively, indicating a
significant renormalization of the spin excitation energies due to exchange
with the Au(111) electrons. Second, a position-dependent bias-asymmetry of the
height of the inelastic steps is accounted for by an interphenalenyl
hybridization of the singly occupied phenalenyl orbitals that is only possible
via third neighbor hopping. This hybridization is also essential to activate
kinetic interphenalenyl exchange. Our results set the stage for future work on
the bottom-up synthesis of spin S = 1/2 spin lattices with large exchange
interaction.
We investigate the dynamical onset of superconductivity in the exactly
solvable Yukawa-Sachdev-Ye-Kitaev model. It hosts an unconventional
superconducting phase that emerges out of a non-Fermi liquid normal state,
providing a toy model for superconductivity in a strongly correlated system.
Analyzing dynamical protocols motivated by theoretical mechanisms proposed for
light-induced superconductivity, that is light-induced cooling and the dressing
of Hamiltonian parameters, we investigate the exact relaxation resulting out of
undercooling and interaction quenches. While, in contrast to BCS theory, it is
not possible for superconductivity to emerge following interaction quenches
across the superconducting phase transition, we find that the dynamical
relaxation of undercooled states universally leads to superconductivity.
Despite the strong correlations, the emerging order parameter dynamics are well
captured by a coarse grained Ginzburg-Landau theory for which we determine all
parameters from microscopics.
We introduce a Brownian $p$-state clock model in two dimensions and
investigate the nature of phase transitions numerically. As a nonequilibrium
extension of the equilibrium lattice model, the Brownian $p$-state clock model
allows spins to diffuse randomly in the two-dimensional space of area $L^2$
under periodic boundary conditions. We find three distinct phases for $p>4$: a
disordered paramagnetic phase, a quasi-long-range-ordered critical phase, and
an ordered ferromagnetic phase. In the intermediate critical phase, the
magnetization order parameter follows a power law scaling $m \sim
L^{-\tilde{\beta}}$, where the finite-size scaling exponent $\tilde{\beta}$
varies continuously. These critical behaviors are reminiscent of the double
Berezinskii-Kosterlitz-Thouless~(BKT) transition picture of the equilibrium
system. At the transition to the disordered phase, the exponent takes the
universal value $\tilde\beta = 1/8$ which coincides with that of the
equilibrium system. This result indicates that the BKT transition driven by the
unbinding of topological excitations is robust against the particle diffusion.
On the contrary, the exponent at the symmetry-breaking transition to the
ordered phase deviates from the universal value $\tilde{\beta} = 2/p^2$ of the
equilibrium system. The deviation is attributed to a nonequilibrium effect from
the particle diffusion.
We investigate the effect of a magnetic field on the band structure of a
bilayer graphene with a magic twist angle of 1.08{\deg}. The coupling of
tight-binding model and Peierls phase allows the calculation of the energy
bands of periodic two-dimensional systems. For an orthogonal magnetic field,
the Landau levels turn out to be dispersive, especially for magnetic lengths
comparable or larger than the twisted bilayer cell size. A high in-plane
magnetic field modifies the low-energy bands and gap, which we demonstrate to
be a direct consequence of the minimal coupling.
Low-energy effective theory of topological orders is topological quantum
field theory (TQFT). While previous field-theoretical studies in $3$D (real
space dimension) topological orders focus on either self-statistics, braiding
statistics, shrinking rules, or fusion rules, it is yet to systematically put
all topological data together and study their internal consistency. Here, we
construct the topological $BF$ field theory with twisted terms (e.g., $AAdA$
and $AAB$) as well as a $K$-matrix $BB$ term, in order to simultaneously
explore all such topological data and reach anomaly-free topological orders. We
present general formulas and show how the $K$-matrix $BB$ term confines
topological excitations, and how self-statistics of particles is transmuted. In
order to reach anomaly-free topological orders, we explore how the principle of
gauge invariance fundamentally influences the compatibility between braiding
statistics and emergent fermions. For example, suppose the flux (loop
excitation) and the charge (particle excitation) of gauge subgroup
$\mathbb{Z}_{N_{i}}$ are denoted as $\phi_{i}$ and $q_{i}$ respectively in a
$3$D bosonic topological order. The field-theoretical analysis simply tells us,
within the present TQFTs, if $\phi_{i}$ nontrivially participates a multi-loop
braiding or a Borromean-rings braiding, then fermionic $q_{i}$ is prohibited
for ensuring the gauge invariance. Therefore, the possible ways of
self-statistics assignment on particles are highly restricted once other
topological data are given. Our analysis provides a field-theoretical approach
to constructing anomaly-free topological orders in $3$D. Together with the
previous efforts, our work paves the way toward a more complete
field-theoretical analysis of $3$D topological orders, in analogy to the
$K$-matrix Chern-Simons theory of $2$D topological orders.
Luminescence of open-shell 3d metal complexes is often quenched due to
ultrafast intersystem crossing (ISC) and cooling into a dark metal-centered
excited state. We demonstrate successful activation of fluorescence from
individual nickel phthalocyanine (NiPc) molecules in the junction of a scanning
tunneling microscope (STM) by resonant energy transfer from other metal
phthalocyanines at low temperature. By combining STM, scanning tunneling
spectroscopy, STM- induced luminescence, and photoluminescence experiments as
well as time-dependent density functional theory, we provide evidence that
there is an activation barrier for the ISC, which in most experimental
conditions is overcome. We show that this is also the case in an
electroluminescent tunnel junction where individual NiPc molecules adsorbed on
an ultrathin NaCl decoupling film on a Ag(111) substrate are probed. However,
when placing an MPc (M = Zn, Pd, Pt) molecule close to NiPc by means of STM
atomic manipulation, resonant energy transfer can excite NiPc without
overcoming the ISC activation barrier, leading to Q-band fluorescence. This
work demonstrates that the thermally activated population of dark
metal-centered states can be avoided by a designed local environment at low
temperatures paired with a directed molecular excitation into vibrationally
cold electronic states. Thus, we can envisage the use of luminophores based on
more abundant transition metal complexes that do not rely on Pt or Ir.
Kagome lattices constitute versatile platforms for studying paradigmatic
correlated phases. While molecular self-assembly of kagome structures on
metallic substrates is promising, it is challenging to realize pristine kagome
properties because of hybridization with the bulk degrees of freedom and
modified electron-electron interactions. We suggest that a superconducting
substrate offers an ideal support for a magnetic kagome lattice. Exchange
coupling induces kagome-derived bands at the interface, which are protected
from the bulk by the superconducting energy gap. We realize a magnetic kagome
lattice on a superconductor by depositing Fe-porphin-chloride molecules on
Pb(111) and using temperature-activated de-chlorination and self-assembly. This
allows us to control the formation of smaller kagome precursors and long-range
ordered kagome islands. Using scanning tunneling microscopy and spectroscopy at
1.6 K, we identify Yu-Shiba-Rusinov states inside the superconducting energy
gap and track their hybridization from the precursors to larger islands, where
the kagome lattice induces extended YSR bands. These YSR-derived kagome bands
are protected inside the superconducting energy gap, motivating further studies
to resolve possible spin-liquid or Kondo-lattice-type behavior.
Fractional charges are one of the wonders of the fractional quantum Hall
effect, a liquid of strongly correlated electrons in a large magnetic field.
Fractional excitations are also anticipated in two-dimensional crystals of
non-interacting electrons under time-reversal symmetry, as bound states of a
rotating bond order known as Kekul\'e vortex. However, the physical mechanisms
inducing such topological defects remain elusive, preventing experimental
realisations. Here, we report the observation of Kekul\'e vortices in the local
density of states of graphene under time-reversal symmetry. The vortices result
from intervalley scattering on chemisorbed hydrogen adatoms and have a purely
electronic origin. Their 2{\pi} winding is reminiscent of the Berry phase {\pi}
of the massless Dirac electrons. Remarkably, we observe that point scatterers
with different symmetries such as divacancies can also induce a Kekul\'e bond
order without vortex. Therefore, our local-probe study further confirms point
defects as versatile building blocks for the control of graphene's electronic
structure by kekul\'e order.
The Weyl-Mott insulator (WMI) has been postulated as a novel type of
correlated insulator with non-trivial topological properties. We introduce a
minimal microscopic model that captures generic features of the WMI transition
in Weyl semimetals. The model hosts a bulk Mott insulator with spinon Fermi
arcs on its surfaces which we identify as a WMI. At finite temperatures, we
find an intermediate Weyl semimetallic phase with no quasiparticles which is
consistent with the bad semimetallic behavior observed in pyrochlore iridates,
A2Ir2O7, close to the Mott transition. Spinon Fermi arcs lead to a suppression
of the bulk Mott gap at the surface of the WMI, in contrast to the gap
enhancement found in conventional Mott insulators, which can be detected
through angular resolved photoemission spectroscopy (ARPES).
We propose a novel approach to the linear viscoelastic problem of
shear-deformable geometrically exact beams. The generalized Maxwell model for
one-dimensional solids is here efficiently extended to the case of arbitrarily
curved beams undergoing finite displacement and rotations. High efficiency is
achieved by combining a series of distinguishing features, that are i) the
formulation is displacement-based, therefore no additional unknowns, other than
incremental displacements and rotations, are needed for the internal variables
associated with the rate-dependent material; ii) the governing equations are
discretized in space using the isogeometric collocation method, meaning that
elements integration is totally bypassed; iii) finite rotations are updated
using the incremental rotation vector, leading to two main benefits: minimum
number of rotation unknowns (the three components of the incremental rotation
vector) and no singularity problems; iv) the same $\rm SO(3)$-consistent
linearization of the governing equations and update procedures as for
non-rate-dependent linear elastic material can be used; v) a standard
second-order accurate time integration scheme is made consistent with the
underlying geometric structure of the kinematic problem. Moreover, taking full
advantage of the isogeometric analysis features, the formulation permits
accurately representing beams and beam structures with highly complex initial
shape and topology, paving the way for a large number of potential applications
in the field of architectured materials, meta-materials, morphing/programmable
objects, topological optimizations, etc. Numerical applications are finally
presented in order to demonstrate attributes and potentialities of the proposed
formulation.
Swimming in low-Reynolds-number fluids requires the breaking of time-reversal
symmetry and centrosymmetry. Microswimmers, often with asymmetric shapes,
exhibit nonreciprocal motions or exploit nonequilibrium processes to propel.
The role of surrounding fluids has also attracted attention because
viscoelastic, non-Newtonian, and anisotropic properties of fluids matter in
propulsion efficiency and navigation. Here we experimentally demonstrate that
anisotropic fluids, nematic liquid crystals (NLC), can make a pulsating
spherical bubble swim despite its centrosymmetric shape and time-symmetric
motion. The NLC breaks the centrosymmetry by a deformed nematic director field
with a topological defect accompanying the bubble. The nematodynamics renders
the nonreciprocity in the pulsation-induced fluid flow. We also report the
speed enhancement by confinement and the propulsion of another symmetry-broken
bubble dressed by a bent disclination. Our experiments and theory elucidate
another possible mechanism of moving bodies in complex fluids by spatiotemporal
symmetry breaking.
The altermagnetism influences the electronic states allowing the presence of
non-relativistic spinsplittings. Since altermagnetic spin-splitting is present
along specific k-paths of the 3D Brillouin zone, we expect that the
altermagnetic surface states will be present on specific surface orientations.
We unveil the properties of the altermagnetic surface states considering three
representative space groups: tetragonal, orthorhombic and hexagonal. We
calculate the 2D projected Brillouin zone from the 3D Brillouin zone. We study
the surfaces with their respective 2D Brillouin zones establishing where the
spin-splittings with opposite sign merge annihilating the altermagnetic
properties and on which surfaces the altermagnetism is preserved. Looking at
the three principal surface orientations, we find that for several cases two
surfaces are blind to the altermagnetism, while the altermagnetism survives for
one surface orientation. Which surface preserves the altermagnetism depends
also on the magnetic order. We show that an electric field orthogonal to the
blind surface can activate the altermagnetism. Our results predict which
surfaces to cleave in order to preserve altermagnetism in surfaces or
interfaces and this paves the way to observe non-relativistic altermagnetic
spin-splitting in thin films via spin-resolved ARPES and to interface the
altermagnetism with other collective modes. We open future perspectives for the
study of altermagnetic effects on the trivial and topological surface states.
The chiral edge current is the boundary manifestation of the Chern number of
a quantum anomalous Hall (QAH) insulator. Its direct observation is assumed to
require well-quantized Hall conductance, and is so far lacking. The recently
discovered van der Waals antiferromagnet MnBi$_2$Te$_4$ is theorized as a QAH
in odd-layers but has shown Hall resistivity below the quantization value at
zero magnetic field. Here, we perform scanning superconducting quantum
interference device (sSQUID) microscopy on these seemingly failed QAH
insulators to image their current distribution. When gated to the charge
neutral point, our device exhibits edge current, which flows unidirectionally
on the odd-layer boundary both with vacuum and with the even-layer. The
chirality of such edge current reverses with the magnetization of the bulk.
Surprisingly, we find the edge channels coexist with finite bulk conduction
even though the bulk chemical potential is in the band gap, suggesting their
robustness under significant edge-bulk scattering. Our result establishes the
existence of chiral edge currents in a topological antiferromagnet and offers
an alternative for identifying QAH states.
The interplay between strong electron correlation and band topology is at the
forefront of condensed matter research. As a direct consequence of correlation,
magnetism enriches topological phases and also has promising functional
applications. However, the influence of topology on magnetism remains unclear,
and the main research effort has been limited to ground state magnetic orders.
Here we report a novel order above the magnetic transition temperature in
magnetic Weyl semimetal (WSM) CeAlGe. Such order shows a number of anomalies in
electrical and thermal transport, and neutron scattering measurements. We
attribute this order to the coupling of Weyl fermions and magnetic fluctuations
originating from a three-dimensional Seiberg-Witten monopole, which
qualitatively agrees well with the observations. Our work reveals a prominent
role topology may play in tailoring electron correlation beyond ground state
ordering, and offers a new avenue to investigate emergent electronic properties
in magnetic topological materials.
Explaining biodiversity is a fundamental issue in ecology. A long-standing
puzzle lies in the paradox of the plankton: many species of plankton feeding on
a limited type of resources coexist, apparently flouting the competitive
exclusion principle (CEP), which holds that the number of predator (consumer)
species cannot exceed that of the resources at steady state. Here, we present a
mechanistic model and show that the intraspecific interference among the
consumers enables a plethora of consumer species to coexist at constant
population densities with only one or a handful of resource species. The
facilitated biodiversity is resistant to stochasticity, either with the
stochastic simulation algorithm or individual-based modeling. Our model
naturally explains the classical experiments that invalidate CEP,
quantitatively illustrates the universal S-shaped pattern of the rank-abundance
curves across a wide range of ecological communities, and can be broadly used
to resolve the mystery of biodiversity in many natural ecosystems.
The duality between deformations of elastic bodies and non-inertial flows in
viscous liquids has been a guiding principle in decades of research. However,
this duality is broken when a spheroidal or other doubly-curved liquid film is
suddenly forced out of mechanical equilibrium, as occurs e.g. when the pressure
inside a liquid bubble drops rapidly due to rupture or controlled evacuation.
In such cases the film may evolve through a non-inertial yet
geometrically-nonlinear surface dynamics, which has remained largely
unexplored. We reveal the driver of such dynamics as temporal variations in the
curvature of the evolving surface. Focusing on the prototypical example of a
floating bubble that undergoes rapid depressurization, we show that the bubble
surface evolves via a topological instability and a subsequent front
propagation, whereby a small planar zone nucleates and expands in the
spherically-shaped film, bringing about hoop compression and triggering
another, symmetry-breaking instability and radial wrinkles that grow in
amplitude and invade the flattening film. Our analysis reveals the dynamics as
a non-equilibrium branch of "Jellium" physics, whereby a rate-of-change of
surface curvature in a viscous film is akin to charge in an electrostatic
medium that comprises polarizable and conducting domains. We explain key
features underlying recent experiments and highlight a qualitative
inconsistency between the prediction of linear stability analysis and the
observed "wavelength" of surface wrinkles. Our analysis points to the existence
of a nonlinear curvature-driven mechanism for pattern selection in viscous
flows.
Active matter spans a wide range of time and length scales, from groups of
cells and synthetic self-propelled particles to schools of fish, flocks of
birds, or even human crowds. The theoretical framework describing these systems
has shown tremendous success at finding universal phenomenology. However,
further progress is often burdened by the difficulty of determining the forces
that control the dynamics of the individual elements within each system.
Accessing this local information is key to understanding the physics dominating
the system and to create the models that can explain the observed collective
phenomena. In this work, we present a machine-learning model, a graph neural
network, that uses the collective movement of the system to learn the active
and two-body forces controlling the individual dynamics of the particles. We
verify our approach using numerical simulations of active brownian particles,
considering different interaction potentials and levels of activity. Finally,
we apply our model to experiments of electrophoretic Janus particles,
extracting the active and two-body forces that control the dynamics of the
colloids. Due to this, we can uncover the physics dominating the behavior of
the system. We extract an active force that depends on the electric field and
also area fraction. We also discover a dependence of the two-body interaction
with the electric field that leads us to propose that the dominant force
between these colloids is a screened electrostatic interaction with a constant
length scale. We expect that this methodology can open a new avenue for the
study and modeling of experimental systems of active particles.
While the $\theta$ dependence of field theories is $2\pi$ periodic, the
ground-state wavefunctions at $\theta$ and $\theta+2\pi$ often belong to
different classes of symmetry-protected topological states. When this is the
case, a continuous change of the $\theta$ parameter can introduce an interface
that supports a nontrivial field theory localized on the wall. We consider the
$2$d $\mathbb{C}P^{N-1}$ sigma model as an example and construct a
weak-coupling setup of this interface theory by considering the small $S^1$
compactification with nonzero winding $\theta$ parameter and a suitable
symmetry-twisted boundary condition. This system has $N$ classical vacua
connected by fractional instantons, but the anomaly constraint tells us that
the fractional-instanton amplitudes should vanish completely to have $N$-fold
degeneracy at the quantum level. We show how this happens in this purely
bosonic system, uncovering that the integration over the zero modes annihilates
the fractional instanton amplitudes, which is sharp contrast to what happens
when the $\theta$ angle is constant. Moreover, we provide another explanation
of this selection rule by showing that the $N$ perturbative vacua acquire
different charges under the global symmetry with the activation of the winding
$\theta$ angle. We also demonstrate a similar destructive interference between
instanton effects in the $\mathbb{C}P^{N-1}$ quantum mechanics with the Berry
phase.
Understanding the fundamental mechanisms of optoelectronic excitation and
relaxation pathways on the single-molecule level has only recently been started
by combining scanning tunneling microscopy (STM) and spectroscopy (STS) with
STM-induced luminescence (STML). In this paper, we investigate cationic and
anionic fluorescence of individual zinc phthalocyanine (ZnPc) molecules
adsorbed on ultrathin NaCl films on Ag(111) by using STML. They depend on the
tip-sample bias polarity and appear at threshold voltages that are correlated
with the onset energies of particular molecular orbitals, as identified by STS.
We also find that the fluorescence is caused by a single electron tunneling
process. Comparing with results from density functional theory calculations, we
propose an alternative many-body picture to describe the charging and
electroluminescence mechanism. Our study provides aspects toward well-defined
voltage selectivity of bipolar electrofluorochromism, as well as fundamental
insights regarding the role of transiently charged states of emitter molecules
within OLED devices.
Chiral magnets can host topological particles known as skyrmions, which carry
an exactly quantised topological charge $Q=-1$. In the presence of an
oscillating magnetic field ${\bf B}_1(t)$, a single skyrmion embedded in a
ferromagnetic background will start to move with constant velocity ${\bf
v}_{\text{trans}}$. The mechanism behind this motion is similar to the one used
by a jellyfish when it swims through water. We show that the skyrmion's motion
is a universal phenomenon, arising in any magnetic system with translational
modes. By projecting the equation of motion onto the skyrmion's translational
modes and going to quadratic order in ${\bf B}_1(t)$, we obtain an analytical
expression for ${\bf v}_{\text{trans}}$ as a function of the system's linear
response. The linear response and consequently ${\bf v}_{\text{trans}}$ are
influenced by the skyrmion's internal modes and scattering states, as well as
by the ferromagnetic background's Kittel mode. The direction and speed of ${\bf
v}_{\text{trans}}$ can be controlled by changing the polarisation, frequency
and phase of the driving field ${\bf B}_1(t)$. For systems with small Gilbert
damping parameter $\alpha$, we identify two distinct physical mechanisms used
by the skyrmion to move. At low driving frequencies, the skyrmion's motion is
driven by friction, and $v_{\text{trans}}\sim\alpha$, whereas at higher
frequencies above the ferromagnetic gap, the skyrmion moves by magnon emission,
and $v_{\text{trans}}$ becomes independent of $\alpha$.
High spin systems, like those that incorporate rare-earth $4f$ elements
(REEs), are increasingly relevant in many fields. Although research in such
systems is sparse, the large Hilbert spaces they occupy are promising for many
applications. In this work, we examine a one-dimensional linear array of
europium (Eu) atoms on a Au(111) surface and study their electronic and
magnetic excitations. Ab initio calculations using VASP with PBE+U are employed
to study the structure. We find Eu atoms to have a net charge when on gold,
consistent with a net magnetic momemt of $\simeq 3.5 \mu_B$. Examining various
spin-projection configurations, we can evaluate first and second neighbor
exchange energies in an isotropic Heisenberg model between spin-$\frac{7}{2}$
moments to obtain $J_1 \approx -1.2 \, \mathrm{K}$ and $J_2 \approx 0.2 \,
\mathrm{K}$ for the relaxed-chain atomic separation of $a \approx 5$
$\mathrm{\dot{A}}$. These parameters are used to obtain the full spin
excitation spectrum of a physically realizable four-atom chain. The large
$|J_1|/J_2$ ratio results in a highly degenerate ferromagnetic ground state
that is split by a significant easy plane single ion anisotropy of $0.6$ K.
Spin-flip excitations are calculated to extract differential conductance
profiles as those obtained by scanning tunneling microscopy techniques. We
uncover interesting behavior of local spin excitations, especially as we track
their dispersion with applied magnetic fields.
Maxwell lattices are characterized by an equal number of degrees of freedom
and constraints. A subset of them, dubbed topological lattices, are capable of
localizing stress and deformation on opposing edges, displaying a polarized
mechanical response protected by the reciprocal-space topology of their band
structure. In two dimensions, the opportunities for topological polarization
have been largely restricted to the kagome and square lattice benchmark
configurations, due to the non-triviality of generating arbitrary geometries
that abide by Maxwell conditions. In this work, we introduce a generalized
family of augmented topological lattices that display full in-plane topological
polarization. We explore the robustness of such polarization upon selection of
different augmentation criteria, with special emphasis on augmented
configurations that display dichotomous behavior with respect to their
primitive counterparts. We corroborate our results via intuitive table-top
experiments conducted on a lattice prototype assembled from 3D-printed
mechanical links.
We investigate electronic states in a two-dimensional network consisting of
interacting quantum wires, a model adopted for twisted bilayer systems. We
construct general operators which describe various scattering processes in the
system. In a twisted bilayer structure, the moir\'e periodicity allows for
generalized umklapp scatterings, leading to a class of correlated states at
certain fractional fillings. We identify scattering processes which can lead to
an insulating gapped bulk with gapless chiral edge modes at fractional
fillings, resembling the quantum anomalous Hall effect recently observed in
twisted bilayer graphene. Finally, we demonstrate that the description can be
useful in predicting spectroscopic and transport features to detect and
characterize the chiral edge modes in the moir\'e-induced correlated states.
We address the general problem of magnetic-field-induced corner states in
quantum spin Hall insulators (QSHIs). Our analytical findings reveal that when
applied to the QSHIs in zinc-blende semiconductor quantum wells (QWs), the
presence of corner states extends beyond the anticipated range of meeting
edges, surpassing the limitations imposed by crystal symmetry. We clearly
demonstrate that, in the most general scenario, magnetic field-induced corner
states in QSHIs are not topological. However, we find that the presence of
crystal symmetry can stabilize these states only under specific orientations of
the in-plane magnetic field and meeting edges. Therefore, contrary to previous
assumptions, our research unveils that QSHIs in the presence of a magnetic
field cannot be accurately considered as higher-order topological insulators.
Furthermore, the lack of an inversion center in zinc-blende semiconductor QWs
enables the emergence of corner states through the influence of a perpendicular
magnetic field.
Photonic topological insulators exhibit bulk-boundary correspondence, which
requires that boundary-localized states appear at the interface formed between
topologically distinct insulating materials. However, many topological photonic
devices share a boundary with free space, which raises a subtle but critical
problem as free space is gapless for photons above the light-line. Here, we use
a local theory of topological materials to resolve bulk-boundary correspondence
in heterostructures containing gapless materials and in radiative environments.
In particular, we construct the heterostructure's spectral localizer, a
composite operator based on the system's real-space description that provides a
local marker for the system's topology and a corresponding local measure of its
topological protection; both quantities are independent of the material's bulk
band gap (or lack thereof). Moreover, we show that approximating radiative
outcoupling as material absorption overestimates a heterostructure's
topological protection. As the spectral localizer is applicable to systems in
any physical dimension and in any discrete symmetry class, our results show how
to calculate topological invariants, quantify topological protection, and
locate topological boundary-localized resonances in topological materials that
interface with gapless media in general.
Single layer $\alpha$-ruthenium trichloride ($\rm\alpha-RuCl_3$) has been
proposed as a potential quantum spin liquid. Graphene/$\rm RuCl_3$
heterobilayers have been extensively studied with a focus on the large
interlayer electron transfer that dopes both materials. Here we examine the
interplay between the competing magnetic state of $\rm RuCl_3$ layer and
graphene electronic properties. We perform self-consistent Hartree-Fock
calculations on a Hubbard-Kanamori model of the $4d^5$ $t_{2g}$ electrons of
$\rm\alpha-RuCl_3$ and confirm that out-of-plane ferromagnetic and zigzag
antiferromagnetic states are energetically competitive. We show that the
influence of hybridization between graphene and $\rm\alpha-RuCl_3$ bands is
strongly sensitive to the magnetic configuration of $\rm RuCl_3$ and the
relative orientations of the two layers. We argue that strong hybridization
leads to graphene magneto-resistance and that it may tilt the balance between
closely competing magnetic states. Our analysis can be applied to any van der
Waals heterobilayer system with weak interlayer hybridization and allows for
arbitrary lattice constant mismatch and relative orientation.
We show that heat production in slowly driven quantum systems is linked to
the topological structure of the driving protocol through the Fubini-Study
tensor. Analyzing a minimal model of a spin weakly coupled to a heat bath, we
find that dissipation is controlled by the quantum metric and a "quality
factor" characterizing the spin's precession. Utilizing these findings, we
establish lower bounds on the heating rate in two-tone protocols, such as those
employed in topological frequency converters. Notably, these bounds are
determined by the topology of the protocol, independent of its microscopic
details. Our results bridge topological phenomena and energy dissipation in
slowly driven quantum systems, providing a design principle for optimal driving
protocols.
The simultaneous occurrence of electric-field controlled superconductivity
and spin-orbit interaction makes two-dimensional electron systems (2DES)
constructed from perovskite transition metal oxides promising candidates for
the next generation of spintronics and quantum computing. It is, however,
essential to understand the electronic bands thoroughly and verify the
predicted electronic states experimentally in these 2DES to advance
technological applications. Here, we present novel insights into the electronic
states of the 2DES at oxide interfaces through comprehensive investigations of
Shubnikov-de Haas oscillations in two different systems: EuO/KTaO$_3$ (EuO/KTO)
and LaAlO$_3$/SrTiO$_3$ (LAO/STO). To accurately resolve these oscillations, we
conducted transport measurements in high magnetic fields up to 60 T and low
temperatures down to 100 mK. For 2D confined electrons at both interfaces, we
observed a progressive increase of oscillations frequency and cyclotron mass
with the magnetic field. We interpret these intriguing findings by considering
the existence of non-trivial electronic bands, for which the $E-k$ dispersion
incorporates both linear and parabolic dispersion relations. In addition to
providing experimental evidence for topological-like electronic states in
KTO-2DES and STO-2DES, the unconventional oscillations presented in this study
establish a new paradigm for quantum oscillations in 2DES based on perovskite
transition metal oxides, where the oscillations frequency exhibits quadratic
dependence on the magnetic field.
Volkov-Pankratov surface bands arise in smooth topological interfaces, i.e.
interfaces between a topological and a trivial insulator, in addition to the
chiral surface state imposed by the bulk-surface correspondence of topological
materials. These two-dimensional bands become Landau-quantized if a magnetic
field is applied perpendicular to the interface. I show that the energy scales,
which are typically in the 10-100 meV range, can be controlled both by the
perpendicular magnetic field and the interface width. The latter can still be
varied with the help of a magnetic-field component in the interface. The Landau
levels of the different Volkov-Pankratov bands are optically coupled, and their
arrangement may allow one to obtain population inversion by resonant optical
pumping. This could serve as the elementary brick of a multi-level laser based
on Landau levels. Moreover, the photons are absorbed and emitted either
parallel or perpendicular to the magnetic field, respectively in the Voigt and
Faraday geometry, depending on the Volkov-Pankratov bands and Landau levels
involved in the optical transitions.

Date of feed: Thu, 20 Jul 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]+) **Quantifying Alignment and Quality of Graphene Nanoribbons: A Polarized Raman Spectroscopy Approach. (arXiv:2307.09490v1 [cond-mat.mtrl-sci])**

Rimah Darawish, Jan Overbeck, Klaus Müllen, Michel Calame, Pascal Ruffieux, Roman Fasel, Gabriela Borin Barin

**Flat-band spin density wave in twisted bilayer materials. (arXiv:2307.09506v1 [cond-mat.str-el])**

Zhigang Song, Jingshan Qi, Olivia Liebman, Prineha Narang

**Dissipative phase transitions and passive error correction. (arXiv:2307.09512v1 [quant-ph])**

Yu-Jie Liu, Simon Lieu

**Impurity screening by defects in (1+1)$d$ quantum critical systems. (arXiv:2307.09519v1 [cond-mat.str-el])**

Ying-Hai Wu, Hong-Hao Tu, Meng Cheng

**Controllable Creation of Skyrmion Bags in a Ferromagnetic Nanodisk. (arXiv:2307.09528v1 [cond-mat.mes-hall])**

Lan Bo, Rongzhi Zhao, Chenglong Hu, Xichao Zhang, Xuefeng Zhang, Masahito Mochizuki

**Yu-Shiba-Rusinov tips: imaging spins at the atomic scale with full magnetic sensitivity. (arXiv:2307.09534v1 [cond-mat.supr-con])**

Felix Küster, Souvik Das, Stuart S. P. Parkin, Paolo Sessi

**On the behaviour of a periodically forced and thermostatted harmonic chain. (arXiv:2307.09535v1 [math-ph])**

Pedro Garrido, Tomasz Komorowski, Joel L. Lebowitz, Stefano Olla

**Large and tunable spin-orbit effect of 6p orbitals through structural cavities in crystals. (arXiv:2307.09545v1 [cond-mat.mtrl-sci])**

Mauro Fava, William Lafargue-Dit-Hauret, Aldo H. Romero, Eric Bousquet

**Moir{\'e} pattern assisted geometric resonant tunneling in disordered twisted bilayer graphene. (arXiv:2307.09587v1 [cond-mat.mes-hall])**

Zhe Hou, Ya-Yun Hu, Guang-Wen Yang

**Theory of anomalous Hall effect in transition-metal pentatelluride $\mathrm{ZrTe}_{5}$ and $\mathrm{HfTe}_{5}$. (arXiv:2307.09708v1 [cond-mat.mes-hall])**

Huan-Wen Wang, Bo Fu, Shun-Qing Shen

**Emergence of two-fold spectral topology through non-Abelian gauge engineering. (arXiv:2307.09757v1 [cond-mat.mes-hall])**

Ronika Sarkar, Ayan Banerjee, Awadhesh Narayan

**Coupling of the triple-Q state to the atomic lattice by anisotropic symmetric exchange. (arXiv:2307.09764v1 [cond-mat.mtrl-sci])**

Felix Nickel, André Kubetzka, Soumyajyoti Haldar, Roland Wiesendanger, Stefan Heinze, Kirsten von Bergmann

**Magneto-transport and electronic structures in MoSi2 bulks and thin films with different orientations. (arXiv:2307.09802v1 [cond-mat.mtrl-sci])**

W. Afzal, F. Yun, Z. Li, Z. Yue, W. Zhao, L. Sang, G. Yang, Y. He, G. Peleckis, M. Fuhrer, X. Wang

**Spin-valley dependent double Andreev reflections in the proximitized graphene/superconductor junction. (arXiv:2307.09833v1 [cond-mat.mes-hall])**

Lu Gao, Qiang Cheng, Qing-Feng Sun

**Lieb-Schultz-Mattis theorem for 1d quantum magnets with antiunitary translation and inversion symmetries. (arXiv:2307.09843v1 [cond-mat.str-el])**

Yuan Yao, Linhao Li, Masaki Oshikawa, Chang-Tse Hsieh

**Hyperbolic non-Abelian semimetal. (arXiv:2307.09876v1 [cond-mat.mes-hall])**

Tarun Tummuru, Anffany Chen, Patrick M. Lenggenhager, Titus Neupert, Joseph Maciejko, Tomáš Bzdušek

**Electrons in helical magnetic field: a new class of topological metals. (arXiv:2307.09884v1 [cond-mat.mtrl-sci])**

Yu. B. Kudasov

**Ultra-Fast All-Electrical Universal Nano-Qubits. (arXiv:2307.09890v1 [cond-mat.mes-hall])**

David T. S. Perkins, Aires Ferreira

**Exchange interactions and intermolecular hybridization in a spin-1/2 nanographene dimer. (arXiv:2307.09930v1 [cond-mat.mes-hall])**

N. Krane, E. Turco, A. Bernhardt, D. Jacob, G. Gandus, D. Passerone, M. Luisier, M. Juríček, R. Fasel, J. Fernández-Rossier, P. Ruffieux

**Dynamical Onset of Light-Induced Unconventional Superconductivity -- a Yukawa-Sachdev-Ye-Kitaev study. (arXiv:2307.09935v1 [cond-mat.supr-con])**

Lukas Grunwald, Giacomo Passetti, Dante M. Kennes

**Nonequilibrium phase transitions in Brownian $p$-state clock model. (arXiv:2307.09945v1 [cond-mat.stat-mech])**

Chul-Ung Woo, Jae Dong Noh

**Magic-angle twisted bilayer graphene under orthogonal and in-plane magnetic fields. (arXiv:2307.09960v1 [cond-mat.mes-hall])**

Gaëlle Bigeard, Alessandro Cresti

**Detecting the interplay between self-statistics and braiding statistics in 3D topologically ordered phases through topological quantum field theory. (arXiv:2307.09983v1 [cond-mat.str-el])**

Zhi-Feng Zhang, Qing-Rui Wang, Peng Ye

**Activating the fluorescence of a Ni(II) complex by energy transfer. (arXiv:2307.09984v1 [cond-mat.mes-hall])**

Tzu-Chao Hung, Yokari Godinez-Loyola, Manuel Steinbrecher, Brian Kiraly, Alexander A. Khajetoorians, Nikos L. Doltsinis, Cristian A. Strassert, Daniel Wegner

**Yu-Shiba-Rusinov bands in a self-assembled kagome lattice of magnetic molecules. (arXiv:2307.09993v1 [cond-mat.mes-hall])**

Laetitia Farinacci, Gael Reecht, Felix von Oppen, Katharina J. Franke

**Observation of Kekul\'e vortices induced in graphene by hydrogen adatoms. (arXiv:2307.10024v1 [cond-mat.mes-hall])**

Y. Guan, C. Dutreix, H. Gonzales-Herrero, M. M. Ugeda, I. Brihuega, M. I. Katsnelson, O. V. Yazyev, V. T. Renard

**Emergence of Spinon Fermi Arcs in the Weyl-Mott Metal-Insulator Transition. (arXiv:2307.10102v1 [cond-mat.str-el])**

Manuel Fernández López, Iñaki García-Elcano, Jorge Bravo-Abad, Jaime Merino

**An efficient displacement-based isogeometric formulation for geometrically exact viscoelastic beams. (arXiv:2307.10106v1 [math.NA])**

Giulio Ferri, Diego Ignesti, Enzo Marino

**Symmetrically pulsating bubbles swim in an anisotropic fluid by nematodynamics. (arXiv:2307.10121v1 [cond-mat.soft])**

Sung-Jo Kim, Žiga Kos, Eujin Um, Joonwoo Jeong

**Altermagnetic surface states: towards the observation and utilization of altermagnetism in thin films, interfaces and topological materials. (arXiv:2307.10146v1 [cond-mat.mtrl-sci])**

Raghottam M Sattigeri, Giuseppe Cuono, Carmine Autieri

**Direct observation of chiral edge current at zero magnetic field in odd-layer MnBi$_2$Te$_4$. (arXiv:2307.10150v1 [cond-mat.mes-hall])**

Jinjiang Zhu, Yang Feng, Xiaodong Zhou, Yongchao Wang, Zichen Lian, Weiyan Lin, Qiushi He, Yishi Lin, Youfang Wang, Hongxu Yao, Hao Li, Yang Wu, Jing Wang, Jian Shen, Jinsong Zhang, Yayu Wang, Yihua Wang

**Fluctuation-driven, topology-stabilized order in a correlated nodal semimetal. (arXiv:2103.08489v2 [cond-mat.str-el] UPDATED)**

Nathan C. Drucker, Thanh Nguyen, Fei Han, Xi Luo, Nina Andrejevic, Ziming Zhu, Grigory Bednik, Quynh T. Nguyen, Zhantao Chen, Linh K. Nguyen, Travis J. Williams, Matthew B. Stone, Alexander I. Kolesnikov, Songxue Chi, Jaime Fernandez-Baca, Tom Hogan, Ahmet Alatas, Alexander A. Puretzky, David B. Geohegan, Shengxi Huang, Yue Yu, Mingda Li

**Intraspecific predator interference promotes biodiversity in ecosystems. (arXiv:2112.05098v3 [q-bio.PE] UPDATED)**

Ju Kang, Shijie Zhang, Xin Wang

**How viscous bubbles collapse: topological and symmetry-breaking instabilities in curvature-driven hydrodynamics. (arXiv:2202.11125v3 [cond-mat.soft] UPDATED)**

Benny Davidovitch, Avraham Klein

**Discovering dynamic laws from observations: the case of self-propelled, interacting colloids. (arXiv:2203.14846v4 [cond-mat.soft] UPDATED)**

Miguel Ruiz-Garcia, C. Miguel Barriuso Gutierrez, Lachlan C. Alexander, Dirk G. A. L. Aarts, Luca Ghiringhelli, Chantal Valeriani

**Winding theta and destructive interference of instantons. (arXiv:2207.03008v2 [hep-th] UPDATED)**

Mendel Nguyen, Yuya Tanizaki, Mithat Ünsal

**Bipolar single-molecule electroluminescence and electrofluorochromism. (arXiv:2210.11118v2 [cond-mat.mes-hall] UPDATED)**

Tzu-Chao Hung, Roberto Robles, Brian Kiraly, Julian H. Strik, Bram A. Rutten, Alexander A. Khajetoorians, Nicolas Lorente, Daniel Wegner

**Skyrmion Jellyfish in Driven Chiral Magnets. (arXiv:2211.01714v5 [cond-mat.mes-hall] UPDATED)**

Nina del Ser, Vivek Lohani

**Spin and electronic excitations in $4f$ atomic chains on Au(111) substrates. (arXiv:2212.08772v2 [cond-mat.mes-hall] UPDATED)**

David W. Facemyer, Naveen K. Dandu, Alex Taekyung Lee, Vijay R. Singh, Anh T. Ngo, Sergio E. Ulloa

**Cell augmentation framework for topological lattices. (arXiv:2301.10376v3 [cond-mat.mtrl-sci] UPDATED)**

Mohammad Charara, Stefano Gonella

**General scatterings and electronic states in the quantum-wire network of moir\'e systems. (arXiv:2303.00759v3 [cond-mat.mes-hall] UPDATED)**

Chen-Hsuan Hsu, Daniel Loss, Jelena Klinovaja

**Magnetic-field-induced corner states in quantum spin Hall insulators. (arXiv:2303.09260v2 [cond-mat.mes-hall] UPDATED)**

Sergey S. Krishtopenko, Frédéric Teppe

**Classifying topology in photonic heterostructures with gapless environments. (arXiv:2303.17135v2 [physics.optics] UPDATED)**

Kahlil Y. Dixon, Terry A. Loring, Alexander Cerjan

**Magnetic States of Graphene Proximitized Kitaev Materials. (arXiv:2305.12116v2 [cond-mat.str-el] UPDATED)**

Jingtian Shi, A.H. MacDonald

**Quantum geometry and bounds on dissipation in slowly driven quantum systems. (arXiv:2306.17220v2 [quant-ph] UPDATED)**

Iliya Esin, Étienne Lantagne-Hurtubise, Frederik Nathan, Gil Refael

**Unconventional quantum oscillations and evidence of non-trivial electronic states in quasi-two-dimensional electron system at complex oxide interfaces. (arXiv:2307.04854v2 [cond-mat.mtrl-sci] UPDATED)**

Km Rubi, Manish Duman, Shengwei Zeng, Andrew Ammerlaan, Femke Bangma, Mun K. Chan, Michel Goiran, Ariando Ariando, Suvankar Chakraverty, Walter Escoffier, Uli Zeitler, Neil Harrison

**Topological interface states -- a possible path towards a Landau-level laser in the THz regime. (arXiv:2307.05116v2 [cond-mat.mes-hall] UPDATED)**

Mark O. Goerbig

Found 6 papers in prb We propose a Monte Carlo simulation to understand electron transport in a nonequilibrium steady state (NESS) for the lattice Coulomb Glass model, created by continuous excitation of single electrons to high energies followed by relaxation of the system. Around the Fermi level, the NESS state approxi… Materials with square lattices composed of group IV or V elements provide a promising platform for topological phases to emerge. We present the study on single crystals of ${\mathrm{LuPb}}_{2}$, which is a compound based on the Pb square net. The de Haas–van Alphen effect measurements reveal clear q… The kagome magnets $R$Mn${}_{6}$Sn${}_{6}$ have recently emerged as a new topological materials platform. By elucidating the topological nature of the band structure, the authors conclude that the observed anomalous Hall conductivity is $u\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}d$ to the previously speculated quasi-two-dimensional Dirac points. The microscopic origin of magnetocrystalline anisotropy is explored at various levels: phenomenological, analytical, and $a\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$. The authors discovered how the special Mn coordination of the rare-earth atoms results in significant high-order anisotropy. The notion of higher-order topological phases can have interesting generalizations to systems with subsystem symmetries that exhibit fractonic dynamics for charged excitations. In this work, we systematically study the higher-order topological phases protected by a combination of subsystem symmetrie… A theoretical principle for explaining the peculiarity in “edge-free” wrinkled graphene has not been firmly established. Herein, we perform DFT calculations to verify the graphene nanowrinkle (GNW) feature on metal as a model system based on experimental observation. We unveil that the interfacial i… We demonstrate the possibility of using time-space crystalline structures to simulate eight-dimensional systems based on only two physical dimensions. A suitable choice of system parameters allows us to obtain a gapped energy spectrum, making topological effects become relevant. The nontrivial topol…

Date of feed: Thu, 20 Jul 2023 03:17:03 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]+) **Variable range hopping in a nonequilibrium steady state**

Preeti Bhandari, Vikas Malik, and Moshe Schechter

Author(s): Preeti Bhandari, Vikas Malik, and Moshe Schechter

[Phys. Rev. B 108, 024203] Published Wed Jul 19, 2023

**Quasilinear magnetoresistance and de Haas–van Alphen quantum oscillations in a ${\mathrm{LuPb}}_{2}$ single crystal**

Feng Yang, Shilong Li, Shengwei Chi, Xiaoxu Wang, Shan Jiang, Huakun Zuo, Lingxiao Zhao, Gang Xu, and Zengwei Zhu

Author(s): Feng Yang, Shilong Li, Shengwei Chi, Xiaoxu Wang, Shan Jiang, Huakun Zuo, Lingxiao Zhao, Gang Xu, and Zengwei Zhu

[Phys. Rev. B 108, 035137] Published Wed Jul 19, 2023

**Interplay between magnetism and band topology in the kagome magnets $R{\mathrm{Mn}}_{6}{\mathrm{Sn}}_{6}$**

Y. Lee, R. Skomski, X. Wang, P. P. Orth, Y. Ren, Byungkyun Kang, A. K. Pathak, A. Kutepov, B. N. Harmon, R. J. McQueeney, I. I. Mazin, and Liqin Ke

Author(s): Y. Lee, R. Skomski, X. Wang, P. P. Orth, Y. Ren, Byungkyun Kang, A. K. Pathak, A. Kutepov, B. N. Harmon, R. J. McQueeney, I. I. Mazin, and Liqin Ke

[Phys. Rev. B 108, 045132] Published Wed Jul 19, 2023

**Classification and construction of interacting fractonic higher-order topological phases**

Jian-Hao Zhang, Meng Cheng, and Zhen Bi

Author(s): Jian-Hao Zhang, Meng Cheng, and Zhen Bi

[Phys. Rev. B 108, 045133] Published Wed Jul 19, 2023

**Anomalous one-dimensional quantum confinement effect in graphene nanowrinkle**

Jong-Guk Ahn, Jee Hyeon Kim, Minhui Lee, Yousoo Kim, Jaehoon Jung, and Hyunseob Lim

Author(s): Jong-Guk Ahn, Jee Hyeon Kim, Minhui Lee, Yousoo Kim, Jaehoon Jung, and Hyunseob Lim

[Phys. Rev. B 108, 045412] Published Wed Jul 19, 2023

**Eight-dimensional topological systems simulated using time-space crystalline structures**

Yakov Braver, Egidijus Anisimovas, and Krzysztof Sacha

Author(s): Yakov Braver, Egidijus Anisimovas, and Krzysztof Sacha

[Phys. Rev. B 108, L020303] Published Wed Jul 19, 2023

Found 1 papers in prl Evidence of coherent light emission from excitons in a 2D-material structure could inspire new quantum-technology applications.

Date of feed: Thu, 20 Jul 2023 03:17:02 GMT**Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+) **Extended Spatial Coherence of Interlayer Excitons in ${\mathrm{MoSe}}_{2}/{\mathrm{WSe}}_{2}$ Heterobilayers**

Mirco Troue, Johannes Figueiredo, Lukas Sigl, Christos Paspalides, Manuel Katzer, Takashi Taniguchi, Kenji Watanabe, Malte Selig, Andreas Knorr, Ursula Wurstbauer, and Alexander W. Holleitner

Author(s): Mirco Troue, Johannes Figueiredo, Lukas Sigl, Christos Paspalides, Manuel Katzer, Takashi Taniguchi, Kenji Watanabe, Malte Selig, Andreas Knorr, Ursula Wurstbauer, and Alexander W. Holleitner

[Phys. Rev. Lett. 131, 036902] Published Wed Jul 19, 2023

Found 2 papers in nano-lett

Date of feed: Wed, 19 Jul 2023 13:04:48 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]+) **[ASAP] Chemical Potential Characterization of Symmetry-Breaking Phases in a Rhombohedral Trilayer Graphene**

Xiangyan Han, Qianling Liu, Yijie Wang, Ruirui Niu, Zhuangzhuang Qu, Zhiyu Wang, Zhuoxian Li, Chunrui Han, Kenji Watanabe, Takashi Taniguchi, Zhida Song, Jinhai Mao, Zheng Vitto Han, Zizhao Gan, and Jianming LuNano LettersDOI: 10.1021/acs.nanolett.3c01262

**[ASAP] Twist-Induced Modification in the Electronic Structure of Bilayer WSe2**

Ding Pei, Zishu Zhou, Zhihai He, Liheng An, Han Gao, Hanbo Xiao, Cheng Chen, Shanmei He, Alexei Barinov, Jianpeng Liu, Hongming Weng, Ning Wang, Zhongkai Liu, and Yulin ChenNano LettersDOI: 10.1021/acs.nanolett.3c01672

Found 2 papers in science-adv

Date of feed: Wed, 19 Jul 2023 19:00:10 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]+) **Coupled topological flat and wide bands: Quasiparticle formation and destruction**

Haoyu Hu and Qimiao Si

Science Advances, Volume 9, Issue 29, July 2023.

**Ultrafast van der Waals diode using graphene quantum capacitance and Fermi-level depinning**

Sungjae Hong, Chang-Ui Hong, Sol Lee, Myeongjin Jang, Chorom Jang, Yangjin Lee, Livia Janice Widiapradja, Sam Park, Kwanpyo Kim, Young-Woo Son, Jong-Gwan Yook, Seongil Im

Science Advances, Volume 9, Issue 29, July 2023.

Found 1 papers in nat-comm **Search terms: **(topolog[a-z]+)|(graphit[a-z]+)|(rhombohedr[a-z]+)|(graphe[a-z]+)|(chalcog[a-z]+)|(landau)|(weyl)|(dirac)|(STM)|(scan[a-z]+ tunne[a-z]+ micr[a-z]+)|(scan[a-z]+ tunne[a-z]+ spectr[a-z]+)|(scan[a-z]+ prob[a-z]+ micr[a-z]+)|(MoS.+\d+|MoS\d+)|(MoSe.+\d+|MoSe\d+)|(MoTe.+\d+|MoTe\d+)|(WS.+\d+|WS\d+)|(WSe.+\d+|WSe\d+)|(WTe.+\d+|WTe\d+)|(Bi\d+Rh\d+I\d+|Bi.+\d+.+Rh.+\d+.+I.+\d+.+)|(BiTeI)|(BiTeBr)|(BiTeCl)|(ZrTe5|ZrTe.+5)|(Pt2HgSe3|Pt.+2HgSe.+3)|(jacuting[a-z]+) **Water nanolayer facilitated solitary-wave-like blisters in MoS2 thin films**

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Found 1 papers in comm-phys Communications Physics, Published online: 19 July 2023; doi:10.1038/s42005-023-01289-8**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]+) **Unusual crossover from Bardeen-Cooper-Schrieffer to Bose-Einstein-condensate superconductivity in iron chalcogenides**

Takasada Shibauchi