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Colloquium: Atomic spin chains on surfacesApr 22 2019In the present Colloquium, we focus on the properties of 1-D magnetic systems on solid surfaces. From the emulation of 1-D quantum phases to the potential realization of Majorana edge states, spin chains are unique systems to study. The advent of scanning ... More

The Structure of Graphene on Graphene/C60/Cu Interfaces: A Molecular Dynamics StudyApr 22 2019Two experimental studies reported the spontaneous formation of amorphous and crystalline structures of C60 intercalated between graphene and a substrate. They observed interesting phenomena ranging from reaction between C60 molecules under graphene to ... More

Amplitude dynamics of charge density wave in LaTe$_3$: theoretical description of pump-probe experimentsApr 22 2019We formulate a dynamical model to describe a photo-induced charge density wave (CDW) quench transition and apply it to recent multi-probe experiments on LaTe$_3$ [A.~Zong \textit{et al.}, Nat. Phys. (2019)]. Our approach relies on coupled time-dependent ... More

Electric field effect in heat transfer between metals in an extreme near fieldApr 21 2019With increasing interest in nanotechnology, the problem of heat transfer between bodies separated by a vacuum gap of just a few nanometers is becoming increasingly important. Calculations of radiative heat transfer between metals in an extreme near field ... More

Brillouin-Mandelstam Spectroscopy of Stress-Modulated Spatially Confined Spin Waves in Ni Thin Films on Piezoelectric HeterostructuresApr 21 2019We report results of micro-Brillouin-Mandelstam light scattering spectroscopy of thermal magnons in the two-phase synthetic multiferroic structure consisting of a piezoelectric (PMN-PT) substrate and a Ni thin film with the thickness of 64 nm. The experimental ... More

Two-electron bound states due to pair spin-orbit interaction in gated layersApr 20 2019We explore the two-electron bound states that arise in two-dimensional gated layers of materials with a strong Rashba spin-orbit interaction. Electron pairing originates from the pair spin-orbit interaction, which appears due to the Coulomb field of the ... More

Force-induced acoustic phonon transport across single-digit nanometre vacuum gapsApr 20 2019Heat transfer between bodies separated by nanoscale vacuum gap distances has been extensively studied for potential applications in thermal management, energy conversion and data storage. For vacuum gap distances down to 20 nm, state-of-the-art experiments ... More

Sub-terahertz ferrimagnetic spin-transfer torque oscillatorApr 19 2019A theory of magnetization dynamics in ferrimagnetic materials with antiparallel aligned spin sub-lattices under action of spin-transfer torques (STT) is developed. We consider magnetization dynamics in GdFeCo layers in two cases of magnetic anisotropy: ... More

Plasmon-Emitter Interactions at the NanoscaleApr 19 2019Plasmon-emitter interactions are of paramount importance in modern nanoplasmonics and are generally maximal at short emitter-surface separations. However, when the separation falls below 10-20 nm, the classical theory progressively deteriorates due to ... More

Phonon localization in surface-roughness dominated nanowiresApr 19 2019Studies of possible localization of phonons in nanomaterials have gained importance in recent years in the context of thermoelectricity where phonon-localization can reduce thermal conductivity, thereby improving the efficiency of thermoelectric devices. ... More

Weyl points in systems of multiple semiconductor-superconductor quantum dotsApr 19 2019As an analogy to the Weyl point in k-space, we search for energy levels which close at a single point as a function of a three dimensional parameter space. Such points are topologically protected in the sense that any perturbation which acts on the two ... More

Chiral sound waves in strained Weyl semimetalsApr 19 2019We show that a strained wire of a Weyl semimetal supports a new type of gapless excitation, the chiral sound wave (CSW). The CSW emerges due to the axial-axial-axial (AAA) triangle anomaly which couples the chiral charge density to elastic axial gauge ... More

Minimizing coherent thermal conductance by controlling the periodicity of two-dimensional phononic crystalsApr 19 2019Periodic hole array phononic crystals (PnC) can strongly modify the phonon dispersion relations, and have been shown to influence thermal conductance coherently, especially at low temperatures where scattering is suppressed. One very important parameter ... More

Topological characterization of hierarchical fractional quantum Hall effects in topological flat bands with SU(N) symmetryApr 19 2019We study the many-body ground states of $N$-component interacting hardcore bosons loaded in topological lattice models with SU$(N)$-symmetric interactions based on exact diagonalization and density matrix renormalization group methods. For strong interactions, ... More

Experimental observation of dynamical bulk-surface correspondence for topological phasesApr 19 2019We experimentally demonstrate a dynamical classification approach for investigation of topological quantum phases using a solid-state spin system through nitrogen-vacancy (NV) center in diamond. Similar to the bulkboundary correspondence in real space ... More

Magnetization control in S/F/S junctions on a 3D topological insulatorApr 18 2019Strong dependence of the Josephson energy on the magnetization orientation in Josephson junctions with ferromagnetic interlayers and spin-orbit coupling opens a way to control magnetization by Josephson current or Josephson phase. Here we investigate ... More

Measuring the Entropy of a Mesoscopic System via Thermoelectric TransportApr 18 2019Entropy is a fundamental thermodynamic quantity indicative of the accessible degrees of freedom in a system. While it has been suggested that the entropy of a mesoscopic system can yield nontrivial information on emergence of exotic states, its measurement ... More

Topological thermal Hall effect of "magnetic monopoles" in pyrochlore U(1) spin liquidApr 18 2019"Magnetic monopole" is an exotic quantum excitation in pyrochlore U(1) spin liquid, and its emergence is purely of quantum origin and has no classical analogue. We predict topological thermal Hall effect (TTHE) of "magnetic monopoles" and present this ... More

Mechanistic insights on the phosphorene degradationApr 18 2019The structural and chemical degradations of phosphorene severely limit its practical applications despite the enormous promise. In this regard, we investigate a plethora of microscopic kinetic mechanisms and develop a degradation phase diagram within ... More

Generalized Berry phase for a bosonic Bogoliubov system with exceptional pointsApr 18 2019We discuss the topology of Bogoliubov excitation bands from a Bose-Einstein condensate in an optical lattice. Since the Bogoliubov equation for a bosonic system is non-Hermitian, complex eigenvalues often appear and induce dynamical instability. As a ... More

THz frequency- and wavevector-dependent conductivity of low-density drifting electron gas in GaN. Monte Carlo calculationsApr 18 2019We report the results of Monte Carlo simulation of electron dynamics in stationary and space- and time-dependent electric fields in compensated GaN samples. We have determined the frequency and wavevector dependencies of the dynamic conductivity, $\sigma_{\omega,q}$. ... More

Many-body perturbation theory and fluctuation relations for interacting population dynamicsApr 18 2019Population dynamics deals with the collective phenomena of living organisms, and it has attracted much attention since it is expected to explain how not only living organisms but also human beings have been adapted to varying environments. However, it ... More

Magnonic Analogue Black/White Hole Horizon in Superfluid $^3$He-B: experimentApr 18 2019We provide experimental details of the first experiment made in zero temperature limit ($\sim$ 600\,$\mu$K) studying the magnonic black/white hole horizon analogue using absolutely pure physical system based on the spin superfluidity in superfluid $^3$He-B. ... More

Switchable out-of-plane polarization in two-dimensional LiAlTe$_2$Apr 18 2019Covalent-polar semiconductors that show intrinsic two-dimensional (2D) vertical polarization present new device opportunities. These materials differ from ordinary ferroelectrics in that they are able to maintain polarization normal to a surface even ... More

Phase coherent transport in bilayer and trilayer MoS2Apr 18 2019Bilayer MoS2 is a centrosymmetric semiconductor with degenerate spin states in the six valleys at the corners of the Brillouin zone. It has been proposed that breaking of this inversion symmetry by an out-of-plane electric field breaks this degeneracy, ... More

Transient Response of the Cavity-Magnon-PolaritonApr 18 2019The Rabi oscillations of a coupled spin-photon system are experimentally studied using time domain microwave transmission measurements. An external magnetic bias field is applied to control the amplitude and frequency of Rabi oscillations, which are a ... More

Direct Measurement of Quantum Efficiency of Single Photon Emitters in Hexagonal Boron NitrideApr 17 2019Single photon emitters in two-dimensional materials are promising candidates for future generation of quantum photonic technologies. In this work, we experimentally determine the quantum efficiency (QE) of single photon emitters (SPE) in few-layer hexagonal ... More

Low temperature saturation of phase coherence length in topological insulatorsApr 17 2019Implementing topological insulators as elementary units in quantum technologies requires a comprehensive understanding of the dephasing mechanisms governing the surface carriers in these materials, which impose a practical limit to the applicability of ... More

Non-Hermitian skin effect and chiral damping in open quantum systemsApr 17 2019One of the unique features of non-Hermitian Hamiltonians is the non-Hermitian skin effect, namely that the eigenstates are exponentially localized at the boundary of system. For open quantum systems, short-time evolution can often be well described by ... More

Fractons from Polarons and Hole-Doped Antiferromagnets: Microscopic Models and RealizationApr 17 2019Fractons are a type of emergent quasiparticle which cannot move freely in isolation, but can easily move in bound pairs. Similar phenomenology is found in boson-affected hopping models, encountered in the study of polaron systems and hole-doped Ising ... More

Connecting the macroscopic phase of a Bardeen-Cooper-Schrieffer condensate to static electric fieldsApr 17 2019The possibility of tuning the properties of BCS metallic superconductors via conventional gating has been excluded for almost a century. Surprisingly, strong static electric fields have been recently shown to modulate the supercurrent down to full suppression ... More

Graphene Induced Large Shift of Surface Plasmon Resonances of Gold Films: Effective Medium Theory for Atomically Thin MaterialsApr 17 2019Despite successful modeling of graphene as a 0.34-nm thick optical film synthesized by exfoliation or chemical vapor deposition (CVD), graphene induced shift of surface plasmon resonance (SPR) of gold films has remained controversial. Here we report the ... More

Current-driven dynamics of magnetic skyrmions in an ultrathin film: experiments and modellingApr 17 2019Magnetic skyrmions are chiral spin textures which hold great promise as nanoscale information carriers. Their recent observation at room temperature and their fast current-induced manipulation in multiple repetitions of heavy metal/ferromagnetic stacks ... More

Current-driven dynamics of magnetic skyrmions in an ultrathin film: experiments and modellingApr 17 2019Apr 18 2019Magnetic skyrmions are chiral spin textures which hold great promise as nanoscale information carriers. Their recent observation at room temperature and their fast current-induced manipulation in multiple repetitions of heavy metal/ferromagnetic stacks ... More

Three-dimensional femtosecond laser nanolithography of crystalsApr 17 2019Nanostructuring hard optical crystals has so far been exclusively feasible at their surface, as stress induced crack formation and propagation has rendered high precision volume processes ineffective. We show that the inner chemical etching reactivity ... More

Orientation dependent current-induced motion of skyrmions with various topologiesApr 17 2019We study the current-driven motion of metastable localized spin structures with various topological charges in a (Pt$_{1-x}$Ir$_{x}$)/Fe bilayer on a Pd(111) surface by combining atomistic spin model simulations with an approach based on the generalized ... More

Signatures of adatom effects in the quasiparticle spectrum of Li-doped grapheneApr 17 2019We study the spectral function and quasiparticle scattering in Li-decorated graphene (Li@graphene) with an atomistic $T$-matrix formalism and uncover adatom-induced spectral effects which shed light on experimentally observed ARPES features. From transport ... More

A cotunneling mechanism for all-electrical Electron Spin Resonance of single adsorbed atomsApr 17 2019The recent development of all-electrical electron spin resonance (ESR) in a scanning tunneling microscope (STM) setup has opened the door to vast applications. Despite the fast growing number of experimental works on STM-ESR, the fundamental principles ... More

Two-orbital effective model for magnetic Weyl semimetal in Kagome-lattice shanditeApr 17 2019We construct a two-orbital effective model for a ferromagnetic Kagome-lattice shandite, $\rm{{Co}_3{Sn}_2{S}_2}$, a candidate material of magnetic Weyl semimetals, by considering one $d$ orbital from Co, and one $p$ orbital from interlayer Sn. The energy ... More

Transient dynamics of pulse-driven memristors in the presence of a stable fixed pointApr 17 2019Some memristors are quite interesting from the point of view of dynamical systems. When driven by narrow pulses of alternating polarities, their dynamics has a stable fixed point, which may be useful for future applications. We study the transient dynamics ... More

Collectively induced exceptional points of quantum emitters coupled to nanoparticle surface plasmonsApr 17 2019Exceptional points, resulting from non-Hermitian degeneracies, have the potential to enhance the capabilities of quantum sensing. Thus, finding exceptional points in different quantum systems is vital for developing such future sensing devices. Taking ... More

Quantum criticality and formation of a singular Fermi liquid in the attractive SU(N > 2) Anderson modelApr 17 2019While much is known about repulsive quantum impurity models, significantly less attention has been devoted to their attractive counterparts. This motivated us to study the attractive SU(N) Anderson impurity model. While for the repulsive case, the phase ... More

Topological carbon allotropes: a proposal for materials innovationApr 17 2019Topology is a central concept of mathematics, which allows us to distinguish two isolated rings with linked ones\cite{Hopf31}. In material science, researchers discovered topologically different carbon allotropes in a form of a cage\cite{Kroto85}, a tube\cite{Iijima91,Ando05}, ... More

Designing Photonic Topological Insulators with Quantum-Spin-Hall Edge States using Topology OptimizationApr 17 2019Designing photonic topological insulators is highly non-trivial because it requires inversion of band symmetries around the band gap, which was so far done using intuition combined with meticulous trial and error. Here we take a completely different approach: ... More

Topological pumping of edge states via adiabatic passageApr 17 2019Topological pumping of edge states in finite crystals or quasicrystals with non-trivial topological phases provides a powerful means for robust excitation transfer. In most schemes of topological pumping, the edge states become delocalized and immersed ... More

Band Tuning of Phosphorene Semiconductor via Floquet TheoryApr 17 2019Graphene and phosphorene are monolayer of graphite and phosphorous, respectively. Graphene is completely relativistic (Dirac) fermionic system, but phosphorene is pseudorelativistic fermionic system. In phosphorene, electronic spectrum of phosphorene ... More

Multifunctional 2D CuSe monolayer nanodeviceApr 17 2019In a very recent experimental work [Gao et al., 2018 Adv. Mater. 30, 1707055], a graphene-like CuSe monolayer was realized. Motivated by this success, we performed first-principles calculations to investigate its electronic transport and photoelectronic ... More

Magnetoterahertz Response and Faraday Rotation from Massive Dirac Fermions in the Topological Crystalline Insulator Pb$_{0.5}$Sn$_{0.5}$TeApr 17 2019Pb$_{1-x}$Sn$_x$Te has been shown to be an interesting tunable topological crystalline insulator system. We present a magneto-terahertz spectroscopic study of thin films of Pb$_{0.5}$Sn$_{0.5}$Te. The complex Faraday rotation angle and optical conductivity ... More

Triplet harvesting in the polaritonic regime: a variational polaron approachApr 16 2019We explore the electroluminescence efficiency for a quantum mechanical model of a large number of molecular emitters embedded in an optical microcavity. We characterize the circumstances under which a microcavity enhances harvesting of triplet excitons ... More

Matter Chern Simons Theories in a Background Magnetic FieldApr 16 2019We study large $N$ 2+1 dimensional fermions in the fundamental representation of an $SU(N)_k$ Chern Simons gauge group in the presence of a uniform background magnetic field for the $U(1)$ global symmetry of this theory. The magnetic field modifies the ... More

Gate-tunable flat bands in van der Waals patterned dielectric superlatticesApr 16 2019Superlattice engineering provides the means to reshape the fabric felt by quasiparticles moving in a material. Here we argue that bandstructure engineering with superlattices can be pushed to the extreme limit by stacking gapped van der Waals (vdW) materials ... More

Identification of superconducting pairing symmetry in twisted bilayer graphene using in-plane magnetic field and strainApr 16 2019We show how the pairing symmetry of superconducting states in twisted bilayer graphene can be experimentally identified by theoretically studying effects of externally applied in-plane magnetic field and strain. In the low field regime, superconducting ... More

Floquet metal to insulator phase transitions in semiconductor nanowiresApr 16 2019We study steady-states of semiconductor nanowires subjected to strong resonant time-periodic drives. The steady-states arise from the balance between electron-phonon scattering, electron-hole recombination via photo-emission, and Auger scattering processes. ... More

Braiding Majorana corner modes in a two-layer second-order topological insulatorApr 16 2019The recent advances in the field of topological materials have established a novel understanding of material physics. Besides theoretical achievements, a number of proposals for decoherence-protected topological quantum computation were provided. It is, ... More

Braiding Majorana corner modes in a two-layer second-order topological insulatorApr 16 2019Apr 22 2019The recent advances in the field of topological materials have established a novel understanding of material physics. Besides theoretical achievements, a number of proposals for decoherence-protected topological quantum computation were provided. It is, ... More

Photocurrent and photoconductance of an helical edge stateApr 16 2019We consider the helical edge state of a Quantum Spin Hall insulator, connected between two leads, and irradiated by a monochromatic and circularly polarized electromagnetic wave. The photocurrent generated within the helical edge state is studied as function ... More

Enhancing spin-orbit torque by strong interfacial scattering from ultra-thin insertion layersApr 16 2019Increasing dampinglike spin-orbit torque (SOT) is both of fundamental importance for enabling new research into spintronics phenomena and also technologically urgent for advancing low-power spin-torque memory, logic, and oscillator devices. Here, we demonstrate ... More

Coherent Magneto-Optomechanical Signal Transduction and Long-Distance Phase-Shift KeyingApr 16 2019A transducer capable of converting quantum information stored as microwaves into telecom-wavelength signals is a critical piece of future quantum technology as it promises to enable the networking of quantum processors. Cavity optomechanical devices that ... More

Energy Stability of Branching in the Scanning Gate Response of Two-Dimensional Electron Gases with Smooth DisorderApr 16 2019Recent experimental and theoretical investigation into the subject of electron flow through two dimensional electron gases (2DEGs) has revealed that the presence of weak, smooth disorder results in "branched flow," a phenomenon in which electron trajectories ... More

Multiple magnon modes in the Co$_3$Sn$_2$S$_2$ Weyl semimetal candidateApr 16 2019We experimentally investigate electron transport in kagome-lattice ferromagnet Co$_3$Sn$_2$S$_2$, which is regarded as a time reversal symmetry broken Weyl semimetal candidate. We demonstrate $dV/dI(I)$ curves with pronounced asymmetric $dV/dI$ spikes, ... More

Quantum Impurity Models coupled to Markovian and Non Markovian BathsApr 16 2019We develop a method to study quantum impurity models, small interacting quantum systems linearly coupled to an environment, in presence of an additional Markovian quantum bath, with a generic non-linear coupling to the impurity. We aim at computing the ... More

Phase-dependent heat transport with unconventional superconductors and superfluidsApr 16 2019We investigate phase-coherent thermal transport in Josephson junctions made from unconventional superconductors or superfluids. The thermal conductance is evaluated for one- and two-dimensional junctions within the Bogoliubov-de Gennes formalism. We analyze ... More

Spontaneous generation of spin current from the vacuum by strong electric fieldsApr 16 2019We discuss spontaneous spin current generation from the vacuum by strong electric fields as a result of interplay between the Schwinger mechanism and a spin-orbit coupling. By considering a homogeneous slow strong electric field superimposed by a fast ... More

Superradiant and transport lifetimes of the cyclotron resonance in the topological insulator HgTeApr 16 2019We investigate the superradiance effects in three-dimensional topological insulator HgTe with conducting surface states. We demonstrate that the superradiance can be explained using the classical electrodynamic approach. Experiments using the continuous-wave ... More

Large tunneling magnetoresistance in VSe2/MoS2 magnetic tunnel junctionApr 16 2019Two-dimensional (2D) van der Waals (vdW) materials provide the possibility of realizing heterostructures with coveted properties. Here, we report a theoretical investigation of the vdW magnetic tunnel junction (MTJ) based on VSe2/MoS2 heterojunction, ... More

Non-Hermitian Majorana Modes Protect Degenerate Steady StatesApr 16 2019Majorana zero modes (MZMs) ensure robust spectral degeneracies in topological phases of superconductors. We demonstrate that non-Hermitian generalizations of MZMs are responsible for a degeneracy in the complex spectrum which describes dynamics of a continuously-observed ... More

Tunable cloaking of Mexican-hat confined states in bilayer siliceneApr 16 2019We present the ballistic quantum transport of a p-n-p bilayer silicene junction in the presence of spin-orbit coupling and electric field using a four-band model in combination with the transfer-matrix approach. A Mexican-hat shape of the low-energy spectrum ... More

Non-equilibrium Green's function predictions of band tails and band gap narrowing in III-V semiconductors and nanodevicesApr 16 2019High-doping induced Urbach tails and band gap narrowing play a significant role in determining the performance of tunneling devices and optoelectronic devices such as tunnel field-effect transistors (TFETs), Esaki diodes and light-emitting diodes. In ... More

Application of single-electron effects to fingerprints of chipsApr 16 2019Single-electron effects have been widely investigated as a typical physical phenomenon in nanoelectronics. The single-electron effect caused by trap sites has been observed in many devices. In general, traps are randomly distributed and not controllable; ... More

Equilibration of Quasi-One-Dimensional Fermi GasesApr 16 2019One-dimensional systems often possess multiple channels or bands arising from the excitation of transverse degrees of freedom. In the present work, we study the specific processes that dominate the equilibration of multi-channel Fermi gases at low temperatures. ... More

Visualizing electrostatic gating effects in two-dimensional heterostructuresApr 15 2019The ability to directly observe electronic band structure in modern nanoscale field-effect devices could transform understanding of their physics and function. One could, for example, visualize local changes in the electrical and chemical potentials as ... More

Higher-order topological insulator out of equilibrium: Floquet engineering and quench dynamicsApr 15 2019Higher order topological (HOT) states, hosting topologically protected modes on lower-dimensional boundaries, such as hinges and corners, have recently extended the realm of the static topological phases. We here demonstrate the possibility of realizing ... More

Topological phases without crystalline counterpartsApr 15 2019We construct a higher-order topological phase protected by a point group symmetry that is impossible in any crystalline system. The tight-binding model describes a superconductor on a quasicrystalline Ammann-Beenker tiling which hosts localized Majorana ... More

Excited states in bilayer graphene quantum dotsApr 15 2019We report on ground- and excited state transport through an electrostatically defined few-hole quantum dot in bilayer graphene in both parallel and perpendicular applied magnetic fields. A remarkably clear level scheme for the two-particle spectra is ... More

Spin-to-charge conversion in magnetic Weyl semimetalsApr 15 2019Weyl semimetals (WSMs) are a newly discovered class of quantum materials which can host a number of exotic bulk transport properties, such as the chiral magnetic effect, negative magneto-resistance, and the anomalous Hall effect. In this work, we investigate ... More

Voltage-tunable Majorana bound states in time-reversal symmetric bilayer quantum spin Hall hybrid systemsApr 15 2019We investigate hybrid structures based on a bilayer quantum spin Hall system in proximity to an s-wave superconductor as a platform to mimic time-reversal symmetric topological superconductors. In this bilayer setup, the induced pairing can be of intra- ... More

Nonequilibrium dynamics of spontaneous symmetry breaking into a hidden state of charge-density waveApr 15 2019Nonequilibrium phase transition plays a pivotal role in a broad physical context from condensed matter to cosmology. Tracking the formation of non-equilibrium phases in condensed matter is challenging and requires a resolution of the long-range cooperativity ... More

Topological Hall effect at above room temperature in heterostructures composed of a magnetic insulator and a heavy metalApr 15 2019Non-volatile memory and computing technology rely on efficient read and write of ultra-tiny information carriers that do not wear out. Magnetic skyrmions are emerging as a potential carrier since they are topologically robust nanoscale spin textures that ... More

Superlattice nanowire heat engines with direction-dependent power output and heat currentApr 15 2019Heat engines (HEs) made of low dimensional structures offer promising applications in energy harvesting due to their reduced phonon thermal conductance. Many efforts have been devoted to the design of HEs made of quantum-dot (QD) superlattice nanowire ... More

Spin-boson model as a simulator of non-Markovian multiphoton Jaynes-Cummings modelsApr 15 2019The paradigmatic spin-boson model considers a spin degree of freedom interacting with an environment typically constituted by a continuum of bosonic modes. This ubiquitous model is of relevance in a number of physical systems where, in general, one has ... More

Catalysis of Dynamical Chiral Symmetry Breaking by Chiral Chemical Potential in Dirac semimetalsApr 15 2019In this paper we study how dynamical chiral symmetry breaking is affected by nonzero chiral chemical potential in Dirac semimetals. To perform this study we applied lattice quantum Monte Carlo simulations of Dirac semimetals. Within lattice simulation ... More

Phonon Topology on the Time-Reversal Symmetric HoneycombApr 15 2019We use the methods of Topological Quantum Chemistry to explore the topology of phonons on time-reversal symmetric crystals with the structure of the planar honeycomb. This approach is not tied to a particular model of atomic vibrations, but is applied ... More

Coulomb blockade in Etched Single and Few Layer MoS2 NanoribbonsApr 15 2019Confinement in two-dimensional transition metal dichalcogenides is an attractive platform for trapping single charge and spins for quantum information processing. Here, we present low temperature electron transport through etched 50-70nm MoS2 nanoribbons ... More

Spin-Orbit-Torque Driven Propagating Spin WavesApr 15 2019Spin-orbit torque (SOT) can drive sustained spin wave (SW) auto-oscillations in a class of emerging microwave devices known as spin Hall nano-oscillators (SHNOs), which have highly non-linear properties governing robust mutual synchronization at frequencies ... More

Composite fermions, rectangular Young tableaux and Gelfand-Tsetlin basis in multicomponent fractional quantum Hall systemsApr 15 2019We put forward a group-theoretical approach to describe the Hilbert space of $M$ fermions, with $N$ components (spin, layer, valley, sub-lattice, etc), per Landau site in the lowest Landau level, at fractional filling factor $\nu=M/\lambda$. The Hilbert ... More

STM Study of Quantum Hall Isospin Ferromagnetic States of Zero Landau Level in Graphene MonolayerApr 15 2019A number of quantum Hall isospin ferromagnetic (QHIFM) states have been predicted in the relativistic zero Landau level (LL) of graphene monolayer. These states, especially the states at LL filling factor v = 0 of charge-neutral graphene, have been extensively ... More

Current-driven nucleation and propagation of antiferromagnetic skyrmioniumApr 15 2019We present a theoretical study on nucleation and propagation of antiferromagnetic skyrmionium induced by spin current injection. A skyrmionium, also known as 2{\pi} skyrmion, is a vortex-like magnetic structure characterized by a topological charge, the ... More

Charge transport of a spin-orbit-coupled Tomonaga-Luttinger liquidApr 15 2019The charge transport of a Tomonaga-Luttinger liquid with tunnel barriers exhibits universal scaling: the current-voltage curves measured at various temperatures collapse into a single curve upon rescaling. The exponent characterizing this single curve ... More

Atomic Localization of Quantum Emitters in Multilayer Hexagonal Boron NitrideApr 15 2019The recent discovery of single-photon emitting defects hosted by the two-dimensional wide band gap semiconductor hexagonal boron nitride (hBN) has inspired a great number of experiments. Key characteristics of these quantum emitters are their capability ... More

Properties of Coupled Single-Electron LinesApr 15 2019Fundamental properties of two electrostatically interacting single-electron lines (SEL) are determined from a minimalistic tight-binding model. The lines are represented by a chain of coupled quantum wells that could be implemented in a mainstream nanoscale ... More

Electronic friction in interacting systemsApr 14 2019We consider effects of strong light-matter interaction on electronic friction in molecular junctions within generic model of single molecule nano cavity junction. Results of the Hubbard NEGF simulations are compared with mean-field NEGF and generalized ... More

Quantitative Electromechanical Atomic Force MicroscopyApr 14 2019The ability to probe a materials electromechanical functionality on the nanoscale is critical to applications from energy storage and computing to biology and medicine. Voltage modulated atomic force microscopy (VM-AFM) has become a mainstay characterization ... More

In-situ strain tuning in hBN-encapsulated graphene electronic devicesApr 14 2019Using a simple setup to bend a flexible substrate, we demonstrate deterministic and reproducible in-situ strain tuning of graphene electronic devices. Central to this method is the full hBN encapsulation of graphene, which preserves the exceptional quality ... More

Nodal surface and persistent spin texture in a Weyl semimetal without mirror symmetryApr 14 2019By utilizing symmetry analysis and electronic structure calculations, we investigated the low-temperature orthorhombic phase of Ag$_{2}$Se in ${\cal SG}$~17. In addition to the discovery of a nodal plane at $k_{z}=\pi$ protected by the joint operation ... More

Direct observation of minibands in twisted heterobilayersApr 14 2019Stacking two-dimensional (2D) van der Waals materials with different interlayer atomic registry in a heterobilayer causes the formation of a long-range periodic superlattice that may bestow the heterostructure with exotic properties such as new quantum ... More

Ultra-Strong Light-Matter Coupling in Deeply Subwavelength THz LC resonatorsApr 14 2019The ultra-strong light-matter coupling regime has been demonstrated in a novel three-dimensional inductor-capacitor (LC) circuit resonator, embedding a semiconductor two-dimensional electron gas in the capacitive part. The fundamental resonance of the ... More

The influence of anti-chiral edge states on Andreev reflection in graphene-superconductor junctionApr 14 2019Using the tight binding model and the non-equilibrium Green function method, we study Andreev reflection in graphene-superconductor junction, where graphene has two nonequal Dirac Cones split in energy and therefore time reversal symmetry is broken. Due ... More

Imaging the stochastic microstructure and dynamic development of correlations in perpendicular artificial spin iceApr 14 2019Apr 16 2019We use spatially resolved magneto-optical Kerr microscopy to track the complete microstates of arrays of perpendicular anisotropy nanomagnets during magnetization hysteresis cycles. These measurements allow us to disentangle the intertwined effects of ... More

Imaging the stochastic microstructure and dynamic development of correlations in perpendicular artificial spin iceApr 14 2019We use spatially resolved magneto-optical Kerr microscopy to track the complete microstates of arrays of perpendicular anisotropy nanomagnets during magnetization hysteresis cycles. These measurements allow us to disentangle the intertwined effects of ... More

Reversible electric-field-driven magnetization in a columnar nanocomposite filmApr 13 2019Magnetic hysteresis loops show a moderate perpendicular anisotropy of the magnetostrictive CFO pillars, which is related to their vertical compression. The application of an electric field to the electromechanical PMN-PT substrate produced significant ... More