Non-Hermitian topological phases have gained widespread interest due to their unconventional properties, which have no Hermitian counterparts. In this work, we propose to use machine learning to identify and predict non-Hermitian topological phases, based on their winding number. We consider two exa...

[Phys. Rev. B 103, 035413] Published Fri Jan 15, 2021

]]>Janus transition metal dichalcogenides (TMDs) lose the horizontal mirror symmetry of ordinary TMDs, leading to the emergence of additional features, such as native piezoelectricity, Rashba effect, and enhanced catalytic activity. While Raman spectroscopy is an essential nondestructive, phase- and co...

[Phys. Rev. B 103, 035414] Published Fri Jan 15, 2021

]]>We investigate the topological properties, energy spectrum, and persistent currents of a non-Hermitian ring with anti-Hermitian hopping terms. It is demonstrated that the anti-Hermitian hopping can effectively induce a synthetic gauge field. As the magnetic flux of the synthetic gauge field threads ...

[Phys. Rev. B 103, 035415] Published Fri Jan 15, 2021

]]>Surface plasmon polaritons (SPPs) due to their subwavelength nature could significantly modify electronic transition behaviors in various optoelectronic systems. Here, using a model system with a spherical quantum dot (QD) close to a flat metal surface, we show that the conventional forbidden optica...

[Phys. Rev. B 103, 035416] Published Fri Jan 15, 2021

]]>We present calculations of the two-photon absorption cross section ${\sigma}^{\left(2\right)}\left(\omega \right)$ for nanocrystals (NCs) of the inorganic perovskite ${\mathrm{CsPbBr}}_{3}$ for photon energies $\omega $ ranging from the absorption threshold at $2\omega \approx 2.3\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$ up to $2\omega =3.1\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$. The calculations employ a $4\times 4\phantom{\rule{4pt}{0ex}}\mathbf{k}\xb7\mathbf{p}$ envelope-function model, with final-state exc...

[Phys. Rev. B 103, 045415] Published Fri Jan 15, 2021

]]>Bound states in the continuum (BICs) have been observed in a variety of systems. A plasmonic BIC offers interesting opportunities, since a surface plasmon is known to confine light to the nanometer scale. However, the observation and manipulation of plasmonic BICs is a challenge due to the intrinsic...

[Phys. Rev. B 103, 045416] Published Fri Jan 15, 2021

]]>Two-dimensional heterostructures and superlattices consisting of transition metal dichalcogenides offer huge potential in the next generation of optoelectronic devices. For such transition metal dichalcogenides, a predictive theory of their properties, based upon in-depth understanding of the interl...

[Phys. Rev. B 103, 045417] Published Fri Jan 15, 2021

]]>In light of the race towards macroscale superlubricity of graphitic contacts, the effect of grain boundaries on their frictional properties becomes of central importance. Here, we elucidate the unique frictional mechanisms characterizing topological defects along typical graphene grain boundaries th...

[Phys. Rev. B 103, 045418] Published Fri Jan 15, 2021

]]>In this paper, the completed investigation of a possible superconducting phase in monolayer indium selenide is determined using first-principles calculations for both the hole and electron doping systems. The hole-doped dependence of the Fermi surface is exclusively fundamental for monolayer InSe. I...

[Phys. Rev. B 103, 035411] Published Thu Jan 14, 2021

]]>One of the most fundamental and exotic properties of three-dimensional (3D) topological insulators (TIs) is spin-momentum locking (SML) of their topological surface states (TSSs), promising for potential applications in future spintronics. However, other possible conduction channels, such as a trivi...

[Phys. Rev. B 103, 035412] Published Thu Jan 14, 2021

]]>We theoretically describe the quantum Zeno effect in a spin-photon interface represented by a charged quantum dot in a micropillar cavity in the strong coupling regime. This simplest model allows for various generalizations for the different systems. We derive a simple expression for the spin measur...

[Phys. Rev. B 103, 045413] Published Thu Jan 14, 2021

]]>We consider a quantum dot weakly tunnel coupled to superconducting reservoirs. A finite superconducting pair amplitude can be induced on the dot via the proximity effect. We investigate the dynamics of the induced pair amplitude after a quench and under periodic driving of the system by means of a r...

[Phys. Rev. B 103, 045414] Published Thu Jan 14, 2021

]]>In this work, we present measurements of the temperature dependence of the resonance Raman spectra of $\mathrm{Mo}{\mathrm{S}}_{2}$ in two-dimensional and bulk forms, performed to identify the processes related to different combinations of two acoustic phonons involved in the intervalley scattering. The resonance Raman spec...

[Phys. Rev. B 103, 045411] Published Wed Jan 13, 2021

]]>Monolayer (ML) transition metal dichalcogenides (TMDCs) emerged as ideal materials to combine spin and momentum of charge carriers for spintronics and valleytronics applications. Despite its relevance for TMDC-based technology, the impact of the various many-body-like interactions of charge carriers...

[Phys. Rev. B 103, 045412] Published Wed Jan 13, 2021

]]>We propose theoretically an effect, i.e., the nonlinear planar Nernst effect (NPNE), in nonmagnetic topological insulator (TI) ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ in the presence of an in-plane magnetic field. We find that the Nernst current scales quadratically with temperature gradient but linearly with magnetic field and exh...

[Phys. Rev. B 103, 035410] Published Tue Jan 12, 2021

]]>We study the delta-$T$ noise in the Kondo regime, which implies the charge current noise under the temperature bias for the SU(2) Kondo quantum dot. We propose an experimentally measurable quantity to quantify the low-temperature properties in the delta-$T$ noise, ${S}_{\ell}=S({T}_{\mathrm{L}},{T}_{\mathrm{R}})-(1/2)[S({T}_{\mathrm{L}},{T}_{\mathrm{L}})+S({T}_{\mathrm{R}},{T}_{\mathrm{R}})]$, w...

[Phys. Rev. B 103, 045409] Published Tue Jan 12, 2021

]]>Superconducting qubits are important for practical implementation of quantum computers. Here, the authors propose a novel type of the superconducting qubit: the spin Weyl quantum unit, a four-state hybrid quantum system that combines states of a spin and an Andreev superconducting qubit. They demonstrate how the unit can be manipulated to achieve an arbitrary unitary transformation in the space of four states by controlling the superconducting phase only, and a convenient readout.

[Phys. Rev. B 103, 045410] Published Tue Jan 12, 2021

]]>Optimal regulation of lattice thermal conductivity in low-dimensional materials is fundamental to obtain highly efficient miniaturized devices. To this aim, we use quantum-mechanical based analyses to understand how atomic type and structural geometry determine electron density and lattice dynamic f...

[Phys. Rev. B 103, 035406] Published Mon Jan 11, 2021

]]>We present an interpretable machine learning model to predict accurately the complex rippling deformations of multiwalled carbon nanotubes made of millions of atoms. Atomistic-physics-based models are accurate but computationally prohibitive for such large systems. To overcome this bottleneck, we ha...

[Phys. Rev. B 103, 035407] Published Mon Jan 11, 2021

]]>In surface-enhanced Raman-scattering experiments that use plasmonic nanostructures as substrates, the scattering spectrum contains a broad background usually associated with photoluminescence. This background exists above and below the frequency of the incident wave. The low-frequency part of this b...

[Phys. Rev. B 103, 035408] Published Mon Jan 11, 2021

]]>The surfaces of rutile transition-metal oxides $\left({\mathrm{TMO}}_{2}\right)$ are widely investigated for catalysis, photoelectrochemical solar cells, memristors, and supercapacitors, but their structures have remained controversial. Here we employ density functional theory to predict that a universal behavior of metallic ${\mathrm{...}}_{}$

[Phys. Rev. B 103, 035409] Published Mon Jan 11, 2021

]]>Twisted bilayer graphene with a twist angle 30° is mapped onto a quasicrystal with a 12-fold rotational symmetry. The authors investigate the quasicrystalline electronic states for every possible two-dimensional twisted bilayer quasicrystal system. The quasicrystalline resonant interaction emerges at specific wave vectors from the combination of the rotational symmetry of the bilayers and the translational symmetries of the constituent layers, as long as all the dominant interlayer interactions occur between the atomic orbitals that have the same magnetic quantum number. In addition, the authors investigate the effects of lifting both interlayer and sublattice symmetry on the respective electronic structures.

[Phys. Rev. B 103, 045408] Published Mon Jan 11, 2021

]]>Calculations of heat transfer between two plates of gold in an extreme near field is performed taking into account the existence of the electrical double layer on metal surfaces. For $d<3\phantom{\rule{0.28em}{0ex}}\mathrm{nm}$ the double layer contribution to the heat flux exceeds the predictions of the conversional theory of the hea...

[Phys. Rev. B 103, L041403] Published Mon Jan 11, 2021

]]>In the linear regime, transport properties of ballistic two-terminal devices are generally considered to be independent of the direction of the current. This two-terminal reciprocity applies to both the electron transmission and reflection probabilities. However, it does not apply to the scattering ...

[Phys. Rev. B 103, 035404] Published Fri Jan 08, 2021

]]>van der Waals (vdW) interaction plays a significant role in controlling the physical properties of layered materials. Typically, the vdW interlayer interaction can be calculated by density functional theory or experimentally characterized by quantum capacitance measurement. Here, we report the probi...

[Phys. Rev. B 103, 035405] Published Fri Jan 08, 2021

]]>The magnetic ratchet effect has been studied in phosphorene by the use of the Boltzmann kinetic equation, which is a semiclassical approach. The Hamiltonian of phosphorene in a steady parallel magnetic field is derived using the tight-binding model. We consider the effect of the magnetic field on no...

[Phys. Rev. B 103, 045406] Published Fri Jan 08, 2021

]]>The surface excitation spectra of the Pd(110) surface is analyzed in the framework of the time-dependent density functional theory. The *ab initio* electronic structure of this surface is included into the evaluation of the surface response function using a linear response approach. At small momentum ...

[Phys. Rev. B 103, 045407] Published Fri Jan 08, 2021

]]>We investigate the electron transport in smooth graphene $p-n$ junctions, generated by gradually varying electrostatic potentials. The numerically calculated coherent current flow patterns can be understood largely in terms of semiclassical trajectories, equivalent to the ones obtained for light beams...

[Phys. Rev. B 103, 045404] Published Thu Jan 07, 2021

]]>For the pristine phosphorene nanoribbons (PNRs) with edge states, there exist two categories of edge bands near the Fermi energy (${E}_{F}$), i.e., the shuttle-shaped twofold-degenerate and the near-flat simple degenerate edge bands. However, the usual experimental measurement may not distinguish the diffe...

[Phys. Rev. B 103, 045405] Published Thu Jan 07, 2021

]]>Quantum Hall ferromagnetic and skyrmion states are commonly encountered in two-dimensional systems in a strong magnetic field. Graphene is special yet again: ferromagnetism does not only involve the spin of the electrons but also their valley “pseudospin.” Since at charge neutrality valley and sublattice are identical, a spin-valley skyrmion has a distinctive spin pattern on the sublattices. The authors characterize a whole skyrmion zoo, where one can obtain, for instance, local antiferromagnetic patterns if the skyrmion is formed solely by spins on a single sublattice.

[Phys. Rev. B 103, 035403] Published Wed Jan 06, 2021

]]>We aim to understand how the spectrum of semi-Dirac fermions is renormalized due to long-range Coulomb electron-electron interactions at a topological Lifshitz transition where two Dirac cones merge. At the transition, the electronic spectrum is characterized by massive quadratic dispersion in one d...

[Phys. Rev. B 103, 045403] Published Wed Jan 06, 2021

]]>We study theoretically second-order topological superconductors characterized by the presence of pairs of zero-energy Majorana corner states. We uncover a quadrupole spin polarization at the system edges that provides a striking signature to identify topological phases, thereby complementing standar...

[Phys. Rev. B 103, L041401] Published Wed Jan 06, 2021

]]>Floquet higher-order topological insulators (FHOTIs) are a novel topological phase that can occur in periodically driven lattices. An appropriate experimental platform to realize FHOTIs has not yet been identified. We introduce a periodically driven bipartite (two-band) system that hosts FHOTI phase...

[Phys. Rev. B 103, L041402] Published Wed Jan 06, 2021

]]>Mostly forsaken, but revived after the emergence of all-dielectric nanophotonics, the Kerker effect can be observed in a variety of nanostructures from high-index constituents with strong electric and magnetic Mie resonances. A necessary requirement for the existence of a magnetic response limits th...

[Phys. Rev. B 103, 035402] Published Tue Jan 05, 2021

]]>We propose an orbital magnetothermal effect wherein a temperature gradient generates an orbital magnetization (OM) for Bloch electrons, and we present a unified theory for electrically and thermally induced OM, valid for both metals and insulators. We reveal that there exists an intrinsic response o...

[Phys. Rev. B 103, 045401] Published Tue Jan 05, 2021

]]>Peierls phase factors multiplying the hopping elements of tight-binding-like Hamiltonians conveniently describe the effect of slowly varying magnetic fields on electrons. This paper provides practical recipes to determine Peierls phase factors such that they preserve the translation symmetry of periodic two-dimensional systems and of quasi-one-dimensional systems that are periodic or with periodic subcomponents, such as Hall bars, in the presence of a homogeneous magnetic field. This allows the applicability of convenient numerical techniques based on the spatial periodicity of the Hamiltonian as demonstrated here on some examples.

[Phys. Rev. B 103, 045402] Published Tue Jan 05, 2021

]]>Atomic steps are typically assumed to only influence surface phenomena of solids. In contrast, here we show, using *in situ* atomic-resolution electron microscopy observations and atomistic modeling, the pronounced effect from surface steps in inducing compositional and structural evolution in the sub...

[Phys. Rev. B 103, 035401] Published Mon Jan 04, 2021

]]>An electron field emission (FE) mechanism, which includes Coulomb blockade and quantum confinement effects, is revealed for heterostructured emitters composed of quantum dots and nanowires self-assembled at diamond nanotips. The total energy distributions of the emitted electrons show multiple peaks...

[Phys. Rev. B 102, 235437] Published Thu Dec 31, 2020

]]>In connection with the recent Harvard group experiment on graphene-based four-terminal Josephson junctions containing a grounded loop, we consider voltage biasing at opposite voltages on the quartet line and establish lowest-order perturbation theory in the tunnel amplitudes between a two-dimensiona...

[Phys. Rev. B 102, 245435] Published Thu Dec 31, 2020

]]>In this paper, we consider a quantum dot connected to four superconducting terminals biased at opposite voltages on the quartet line. The grounded superconductor contains a loop threaded by the magnetic flux $\mathrm{\Phi}$. We provide Keldysh microscopic calculations and physical pictures for the voltage-$V$ depen...

[Phys. Rev. B 102, 245436] Published Thu Dec 31, 2020

]]>The specific heat of a two-layer ${}^{4}\mathrm{He}$ film adsorbed on a graphite substrate is estimated as a function of temperature by quantum Monte Carlo simulations. The results are consistent with recent experimental observations [S. Nakamura, K. Matsui, T. Matsui, and H. Fukuyama, Phys. Rev. B **94**, 180501(R) (2...

[Phys. Rev. B 102, 235436] Published Wed Dec 30, 2020

]]>Twisted nanoribbons from two-dimensional materials possess many unusual properties tunable by changing the twist angle, for example, electro- and thermal conductivity, chemical properties, and stability against buckling. New interesting phenomena can be observed when a twisted nanoribbon interacts w...

[Phys. Rev. B 102, 245432] Published Wed Dec 30, 2020

]]>Quantum systems can undergo phase transitions and show distinct features in different phases. The corresponding transport properties can also vary significantly due to the underlying quantum phase. We investigate the transport behavior of a two-legged bosonic ladder in a uniform gauge field, which i...

[Phys. Rev. B 102, 245433] Published Wed Dec 30, 2020

]]>We study the response of a Dirac fluid to electric fields and thermal gradients at finite wave numbers and frequencies in the hydrodynamic regime. We find that nonlocal transport in the hydrodynamic regime is governed by an infinite set of kinetic modes that describe noncollinear scattering events i...

[Phys. Rev. B 102, 245434] Published Wed Dec 30, 2020

]]>The electrostatic properties of defects of the Si(111)-$(\sqrt{3}\times \sqrt{3}){R}^{\circ}30$ surface are studied using noncontact atomic force microscopy and Kelvin probe force microscopy with subnanometer resolution and subelementary charge sensitivity. We identify nonparabolicities in the frequency-voltage spectroscopy of si...

[Phys. Rev. B 102, 235433] Published Tue Dec 29, 2020

]]>Despite the intense amount of attention and huge potential of two-dimensional (2D) magnets for applications in novel magnetic, magneto-optical, magnetothermal, and magnetoelectronic devices, there is a lack of robust strategy developed to systematically understand magnon-magnon interactions (MMIs) a...

[Phys. Rev. B 102, 235434] Published Tue Dec 29, 2020

]]>In a recent work, new two-dimensional materials, monolayer ${\mathrm{MoSi}}_{2}{\mathrm{N}}_{4}$ and ${\mathrm{WSi}}_{2}{\mathrm{N}}_{4}$, were successfully synthesized in experiment, and several other monolayer materials with a similar structure, such as ${\mathrm{MoSi}}_{2}{\mathrm{As}}_{4}$, were predicted [Hong *et al.*, Science **369**, 670 (2020)]. Here, based on first-principles calcul...

[Phys. Rev. B 102, 235435] Published Tue Dec 29, 2020

]]>We report a two-dimensional artificial lattice for dipolar excitons confined in a GaAs double quantum well. Exploring the regime of large fillings per lattice site, we verify that the lattice depth competes with the magnitude of exciton repulsive dipolar interactions to control the degree of localiz...

[Phys. Rev. B 102, 245428] Published Tue Dec 29, 2020

]]>We present theoretical studies of temperature dependent diamagnetic-paramagnetic transitions in thin quantum rings. Our studies show that the magnetic susceptibility of metal/semiconductor rings can exhibit multiple sign flips at intermediate and high temperatures depending on the number of conducti...

[Phys. Rev. B 102, 245429] Published Tue Dec 29, 2020

]]>We develop a method of theoretically investigating the charge, energy, and heat transport in the presence of the charge Kondo correlations. The Coulomb blockade oscillations of heat conductance in the single-electron transistor exhibiting charge Kondo effects are investigated. We explore the Wiedema...

[Phys. Rev. B 102, 245430] Published Tue Dec 29, 2020

]]>We consider a two-dimensional electron gas (2DEG) with Rashba spin-orbit interaction (SOI) partially covered by an $s$-wave superconductor, where the uncovered region remains normal but is exposed to a perpendicular Zeeman field. We find analytically and numerically Andreev bound states (ABSs) formed ...

[Phys. Rev. B 102, 245431] Published Tue Dec 29, 2020

]]>As an emerging complex two-dimensional structure, plane fractal has attracted much attention due to its novel dimension-related physical properties. In this paper, we check the feasibility to create an effective Sierpinski carpet (SC), a plane fractal with Hausdorff dimension intermediate between on...

[Phys. Rev. B 102, 245425] Published Mon Dec 28, 2020

]]>The Berry phase effect plays a central role in many mesoscale condensed matter and quantum chemical systems that are naturally under the environmental influence of dissipation. We propose and microscopically derive a prototypical quantum coherent tunneling model around a monopole or conical potentia...

[Phys. Rev. B 102, 245426] Published Mon Dec 28, 2020

]]>The strain fields of periodically buckled graphene induce a periodic pseudomagnetic field (PMF) that modifies the electronic band structure. From the geometry, amplitude, and period of the periodic pseudomagnetic field, we determine the necessary conditions to access the regime of correlated phases ...

[Phys. Rev. B 102, 245427] Published Mon Dec 28, 2020

]]>A theory of electron spin-flip Raman scattering (SFRS) is presented that describes the Raman spectral signals shifted by both one and two times the electron Zeeman energy under nearly resonant excitation of the heavy hole excitons in semiconductor nanoplatelets. We analyze the spin structure of phot...

[Phys. Rev. B 102, 235432] Published Thu Dec 24, 2020

]]>The dominant role of strong electron-electron interactions in driving two-dimensional metal-insulator transitions has long been debated, but its clear experimental demonstration is still not available. Here, we examine the finite-temperature transport behavior of few-layered ${\mathrm{MoS}}_{2}$ material in the vic...

[Phys. Rev. B 102, 245424] Published Thu Dec 24, 2020

]]>A two-dimensional graphene isotope superlattice lattice of carbon 12 and carbon 13 shows a fascinating Raman scattering response: two phonons from different isotope regions are emitted in a single Raman process, leading to the tripling of the corresponding Raman peak. This occurs when the mean free path of the photoexcited electron is larger than the superlattice period and can be understood in terms of a real-space picture of Raman scattering.

[Phys. Rev. B 102, 235429] Published Wed Dec 23, 2020

]]>This work uncovers a hitherto unknown connection between different effects mediated by spin-orbit coupling in nanostructures: spin transport, weak antilocalization, and spin-triplet superconductivity. The authors show that all these phenomena can be described by a tool borrowed from the theory of superconductivity – the linearized Eilenberger equation, generalized to include the spin-orbit coupling as a non-Abelian background gauge field. Furthermore, this approach enables the description of the aforementioned phenomena in a simpler and more intuitive manner compared to other methods.

[Phys. Rev. B 102, 235430] Published Wed Dec 23, 2020

]]>Through a thorough magnetotransport study of antiferromagnetic topological insulator $\mathrm{Mn}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$ (MBT) thick films, a positive linear magnetoresistance (LMR) with a two-dimensional (2D) character is found in high perpendicular magnetic fields and at temperatures up to at least 260 K. The nonlinear Hall...

[Phys. Rev. B 102, 235431] Published Wed Dec 23, 2020

]]>Materials with reduced dimensionality often exhibit exceptional properties that are different from their bulk counterparts. Here, we report the emergence of a commensurate $2\times 2$ charge density wave (CDW) in monolayer and bilayer ${\mathrm{SnSe}}_{2}$ films by scanning tunneling microscopy. The visualized spatial modu...

[Phys. Rev. B 102, 241408(R)] Published Tue Dec 22, 2020

]]>The hydrodynamic regime of electron transport has been recently realized in conductors with ultralow densities of defects. Although relaxation processes in two-dimensional (2D) fluids have been studied in many theoretical works, the viscosity of the realistic Fermi gas of 2D electrons having a quadr...

[Phys. Rev. B 102, 241409(R)] Published Tue Dec 22, 2020

]]>Metasurfaces, the two-dimensional counterparts of three-dimensional metamaterials, have recently attracted much attention due to their interesting properties, such as negative refraction, hyperbolic dispersion, and the ability to manipulate the evanescent spectrum. In this work, we propose a theoret...

[Phys. Rev. B 102, 245421] Published Tue Dec 22, 2020

]]>A nonlinear scheme of high-harmonic generation in a wide class of time-reversal invariant materials with broken spatial inversion symmetry (for which, recently, the nonlinear Hall effect was established) due to the nontrivial topology of bands is proposed. A microscopic quasiclassical theory describ...

[Phys. Rev. B 102, 245422] Published Tue Dec 22, 2020

]]>The vertical electric field response of dark- and bright-excitonic fine structures in self-assembled quantum dots remains largely unexplored. Using an atomistic tight-binding model, combined with a configuration-interaction approach, we show that the fine structure of both bright and dark excitons c...

[Phys. Rev. B 102, 245423] Published Tue Dec 22, 2020

]]>We obtain an analytical expression for the heat current between two overdamped quantum oscillators interacting with local thermal baths at different temperatures. The total heat current is split into classical and quantum contributions. We show how to evaluate both contributions by taking advantage ...

[Phys. Rev. B 102, 235422] Published Mon Dec 21, 2020

]]>The authors demonstrate that in moiré transition metal dichalcogenide bilayers strong electron repulsion alone is sufficient to create tightly bound charge-2$e$ bosons called trimers. They consist of two holes bound to a charge-transfer exciton. When the bandwidth of doped holes is small, trimers crystallize into insulating pair density waves. By varying the twist angle to increase the bandwidth, holes and trimers can be tuned to resonance, leading to unconventional superconductivity similar to superfluidity in an ultracold Fermi gas near a Feshbach resonance.

[Phys. Rev. B 102, 235423] Published Mon Dec 21, 2020

]]>Anomalous behavior of spin stiffness is revealed in ZnO-based two-dimensional electron systems (2DESs) with strong Coulomb interaction and Wigner-Seitz parameter ${r}_{s}>6$. The spin stiffness is extracted directly from the quadratic $k$ dispersion of spin excitons at $\nu =1$ probed by inelastic light scatte...

[Phys. Rev. B 102, 235424] Published Mon Dec 21, 2020

]]>We report on the direct measurement of the electron spin splitting and the accompanying nuclear Overhauser field, and thus the underlying nuclear spin polarization (NSP) and fluctuation bandwidth, in a single InAs quantum dot under resonant excitation conditions with unprecedented spectral resolutio...

[Phys. Rev. B 102, 235425] Published Mon Dec 21, 2020

]]>A valley-contrasting Berry curvature in bilayer transition metal dichalcogenides with spin-orbit coupling can generate valley magnetization when the inversion symmetry is broken, for example, by an electric field, regardless of time-reversal symmetry. A nontrivial Berry curvature can also lead to an...

[Phys. Rev. B 102, 235426] Published Mon Dec 21, 2020

]]>We propose a quantum absorption refrigerator using the quantum physics of resonant tunneling through quantum dots. The cold and hot reservoirs are fermionic leads, tunnel coupled via quantum dots to a central fermionic cavity, and we propose configurations in which the heat absorbed from the (very h...

[Phys. Rev. B 102, 235427] Published Mon Dec 21, 2020

]]>Topological phase transitions occur when the electronic bands change their topological properties, typically featuring the closing of the band gap. While the influence of topological phase transitions on electronic and optical properties has been extensively studied, its implication on phononic prop...

[Phys. Rev. B 102, 235428] Published Mon Dec 21, 2020

]]>We derive the formula for the near-field radiative heat transfer between dipole particles and a multilayered slab by combing the transmission Green's function and transfer matrix method. In this framework we study the radiative heat transfer (RHT) from a multilayered slab to a particle and the many-...

[Phys. Rev. B 102, 245418] Published Mon Dec 21, 2020

]]>Anisotropy is a general feature in materials. Strong anisotropy could lead to interesting physical properties and useful applications. Here, based on first-principles calculations and theoretical analysis, we predict a stable two-dimensional (2D) material—the monolayer ${\mathrm{MoOCl}}_{2}$—and show that it posses...

[Phys. Rev. B 102, 245419] Published Mon Dec 21, 2020

]]>We examine the heat and charge transport of a driven topological superconductor. Our particular system of interest consists of a Y-junction of topological superconducting wires, hosting non-Abelian Majorana zero modes at their edges. The system is contacted to two leads which act as continuous detec...

[Phys. Rev. B 102, 245420] Published Mon Dec 21, 2020

]]>We present time-dependent density functional molecular dynamics (TDDFT-MD) simulations with an adiabatic approximation to the exchange-correlation potential for hyperthermal protons (${\mathrm{H}}^{+}$) with initial kinetic energies in the range of 2–50 eV impinging on the fcc-hollow site and the on-top site of an ...

[Phys. Rev. B 102, 235421] Published Thu Dec 17, 2020

]]>The spintronic properties of curved nanostructures derived from two-dimensional topological insulators (2DTIs) are explored theoretically with density functional theory (DFT)-based calculations and tight-binding models. We show that curved geometries make it possible to manipulate electron spins in ...

[Phys. Rev. B 102, 235420] Published Wed Dec 16, 2020

]]>Two-dimensional (2D) $A$-type antiferromagnetic van der Waals (vdW) materials with either intralayer ferromagnetic and/or intralayer antiferromagnetic coupling have sparked great interest due to their potential applications in spintronics. By first-principles design we predict that a heterostructure f...

[Phys. Rev. B 102, 245417] Published Wed Dec 16, 2020

]]>The recently discovered antiferromagnetic 1/1 Au-Al-Tb approximant exhibits a whirling spin order oriented along the [111] direction. Here we report an investigation of the atomic structure of the (111) surface by scanning tunneling microscopy and density functional theory (DFT) calculations. Scanni...

[Phys. Rev. B 102, 235419] Published Tue Dec 15, 2020

]]>Using Floquet theory, we investigate the effect of light on triplefold fermions. We study a low-energy model as well as a simplified tight-binding model under illumination. We find that the threefold degeneracy remains symmetry protected even after applying light if the original band structure is ro...

[Phys. Rev. B 102, 245416] Published Tue Dec 15, 2020

]]>The voltage dependences of conductivity, $\sigma \left(V\right)$, of the monoclinic phase of ${\mathrm{NbS}}_{3}$ are reported. The extremely high coherence of the room-temperature charge density wave (CDW) allows its synchronization by a rf field up to ${T}_{\mathrm{P}1}\approx 365\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, the temperature of the Peierls transition, and above it by about 10 K. ...

[Phys. Rev. B 102, 235415] Published Mon Dec 14, 2020

]]>Electron exchange and correlations emerging from the coupling between ionic vibrations and electrons are addressed. Spin-dependent electron-phonon coupling originates from the spin-orbit interaction, and it is shown that such electron-phonon coupling introduces exchange splitting between the spin ch...

[Phys. Rev. B 102, 235416] Published Mon Dec 14, 2020

]]>We performed imaging and manipulation of epitaxially grown Pb adatom structures on the Si(100) surface by noncontact atomic force microscopy (NC-AFM) in ultra-high-vacuum (UHV) and at cryogenic temperatures. We observe several distinct contrast modes during imaging, which we assign to termination of...

[Phys. Rev. B 102, 235417] Published Mon Dec 14, 2020

]]>In the emerging world of twisted bilayer structures, the possible configurations are limitless, which enables a rich landscape of electronic properties. In this paper, we focus on twisted bilayer transition metal dichalcogenides (TMDCs) and study their properties by means of an accurate tight-bindin...

[Phys. Rev. B 102, 235418] Published Mon Dec 14, 2020

]]>Recently, the intrinsic magnetic topological insulator ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$ has attracted great attention. It has an out-of-plane antiferromagnetic order, which is believed to open a sizable energy gap in the surface states. This gap, however, was not always observable in the latest angle-resolved photoemission...

[Phys. Rev. B 102, 241406(R)] Published Mon Dec 14, 2020

]]>In the framework of time-dependent density-functional theory, we obtain high-order harmonics of photon energies up to $10\phantom{\rule{0.16em}{0ex}}\phantom{\rule{0.16em}{0ex}}{U}_{p}$ from bilayer crystals with an interlayer spacing $d=70\phantom{\rule{0.16em}{0ex}}\AA $. At grazing incidence, a clear double-plateau structure is observed in the harmonic spectrum. The photon energy of the sec...

[Phys. Rev. B 102, 241407(R)] Published Mon Dec 14, 2020

]]>We analyze theoretically quench dynamics of a two-site system abruptly driven from its equilibrium state focusing on the time dependent spectral density function. In the presence of electron reservoirs this function reveals in time a nontrivial regular pattern of peaks corresponding to the stationar...

[Phys. Rev. B 102, 245414] Published Mon Dec 14, 2020

]]>Through a combination of atomistic spin-lattice dynamics simulations and relativistic *ab initio* calculations of electronic transport we shed light on unexplained electrical measurements in nickel nanocontacts created by break junction experiments under cryogenic conditions (4.2 K). We implement post...

[Phys. Rev. B 102, 245415] Published Mon Dec 14, 2020

]]>Artificial hyperbolic metamaterials (HMM) are perspective for the nonlinear optical applications, their exciting functionality being due to the hyperbolic dispersion induced by a strong shape anisotropy. Here we study the second harmonic generation (SHG) in HMM formed by arrays of silver nanorods in...

[Phys. Rev. B 102, 241405(R)] Published Fri Dec 11, 2020

]]>Based on the nontrivial topology of buckled antimonene, we propose two conceptual device designs based on breaking the inversion symmetry which can be achieved by gating. The first one is a quantized topological switch obtained by breaking the degeneracy of the fractionalized charge conducting edge ...

[Phys. Rev. B 102, 245413] Published Fri Dec 11, 2020

]]>Physical properties of a topological origin are known to be robust against small perturbations. This robustness is both a source of theoretical interest and a driver for technological applications, but presents a challenge when looking for new topological systems: Small perturbations cannot be used ...

[Phys. Rev. B 102, 241404(R)] Published Thu Dec 10, 2020

]]>We theoretically investigate the thermoelectric transport in the nanoribbon of the magnetic topological insulator with a domain wall in the linear and nonlinear regimes. The Lorenz number $L$, the Seebeck coefficients ${S}_{c}$, and the thermoelectrical figure of merit $ZT$ in the linear response regime are ob...

[Phys. Rev. B 102, 245412] Published Thu Dec 10, 2020

]]>The passage of an electric current in a material can cause a biased mass transport at its surface. This migration phenomenon is intimately related to the microscopic details of atomic processes of diffusion and attachment/detachment at step edges. Using low-energy electron microscopy, we have examin...

[Phys. Rev. B 102, 235412] Published Wed Dec 09, 2020

]]>We report on theoretical and experimental study of the spin polarization recovery and Hanle effect for the charge carriers interacting with the fluctuating nuclear spins in the semiconductor structures. We start the theoretical description from the simplest model of static and isotropic nuclear spin...

[Phys. Rev. B 102, 235413] Published Wed Dec 09, 2020

]]>The nondispersive flat band in the $\alpha \text{\u2212}{T}_{3}$ model leads to a conventional integer quantum Hall effect (IQHE) for Dirac particles as well as the existence of the zero Hall-conductivity plateau ($\nu =0$) at the band center. In this work, we study the broken-flat-band effect on the IQHE by introducing the diso...

[Phys. Rev. B 102, 235414] Published Wed Dec 09, 2020

]]>Understanding strongly interacting electrons enables the design of materials, nanostructures, and devices. Developing this understanding relies on the ability to tune and control electron-electron interactions by, e.g., confining electrons to atomically thin layers of two-dimensional crystals with r...

[Phys. Rev. B 102, 245410] Published Wed Dec 09, 2020

]]>Both applied electric currents and magnetization dynamics modify the Dzyaloshinskii-Moriya interaction (DMI), which we call current-induced DMI (CIDMI) and dynamical DMI (DDMI), respectively. We report a theory of CIDMI and DDMI. The inverse of CIDMI consists in charge pumping by a time-dependent gr...

[Phys. Rev. B 102, 245411] Published Wed Dec 09, 2020

]]>Despite recent transport studies of *ABC*-stacked multilayer graphene systems revealed various unusual quantum phenomena which arise from the nearly flat electronic bands, their quantum tunneling properties have rarely been addressed. Here we investigate the local tunneling characteristics of a gapped...

[Phys. Rev. B 102, 241403(R)] Published Tue Dec 08, 2020

]]>We present a detailed study of the time-resolved photoluminescence of narrow-line emission centers in $\mathrm{W}{\mathrm{Se}}_{2}$ monolayers and bilayers. Our experiments reveal noninstantaneous photoluminescence intensity rise after the laser pulse. This shows that the simplest excitation model in which the localized sta...

[Phys. Rev. B 102, 245409] Published Tue Dec 08, 2020

]]>A recently proposed two-dimensional (2D) carbon allotrope, tetrahex-carbon composed of tetragonal and hexagonal rings in a buckled plane, draws scientific research interests due to its remarkable mechanical and electronic properties, including ultrahigh strength, negative Poisson's ratio, finite dir...

[Phys. Rev. B 102, 235409] Published Mon Dec 07, 2020

]]>Strain-inducing deformations in graphene alter charge distributions and provide a new method to design specific features in the band structure and transport properties. Novel approaches implement engineered substrates to induce specifically targeted strain profiles. Motivated by this technique, we s...

[Phys. Rev. B 102, 235410] Published Mon Dec 07, 2020

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