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A simple view on the quantum Hall system: The physics of the quantum Hall system becomes very simple when studied on a thin torus. Remarkably, however, the very rich structure still exists in this limit and there is a continuous route to the bulk system. Here we review recent progress in understanding various features ...
cond-mat_mes-hall
Spin waves in zigzag graphene nanoribbons and the stability of edge ferromagnetism: We study the low energy spin excitations of zigzag graphene nanoribbons of varying width. We find their energy dispersion at small wave vector to be dominated by antiferromagnetic correlations between the ribbon's edges, in accrodance...
cond-mat_mes-hall
Saturation and bistability of defect-mode intersubband polaritons: In this article we report about linear and nonlinear optical properties of intersubband cavity polariton samples, where the resonant photonic mode is a defect state in a metallo-dielectric photonic crystal slab. By tuning a single geometric parameter of...
cond-mat_mes-hall
Ligand effects on the electronic structure and magnetism of magnetite surfaces: We address the effect of functionalization on the electronic and magnetic properties of magnetite surface as an indicator of the same properties in nanoparticles too big for a direct ab-initio approach. Using well-established methods and ...
cond-mat_mes-hall
High temperature magnetism and microstructure of semiconducting ferromagnetic alloy (GaSb)$_{1-x}$(MnSb)$_{x}$: We have studied the properties of relatively thick (about 120 nm) magnetic composite films grown by pulsed laser deposition method using (GaSb)$_{0.59}$(MnSb)$_{0.41}$ eutectic compound as a target for sput...
cond-mat_mes-hall
Quantum Coherent Multielectron Processes in an Atomic Scale Contact: The light emission from a scanning tunneling microscope operated on a Ag(111) surface at 6 K is analyzed from low conductances to values approaching the conductance quantum. Optical spectra recorded at a sample voltages V reveal emission with photon e...
cond-mat_mes-hall
Anomalous Spin Dephasing in (110) GaAs Quantum Wells: Anisotropy and Intersubband Effects: A strong anisotropy of electron spin decoherence is observed in GaAs/(AlGa)As quantum wells grown on (110) oriented substrate. The spin lifetime of spins perpendicular to the growth direction is about one order of magnitude sho...
cond-mat_mes-hall
On the nature of the spin polarization limit in the warped Dirac cone of the Bi2Te3: The magnitude of electron spin polarization in topologically protected surface states is an important parameter with respect to spintronics applications. In order to analyze the warped spin texture in Bi$_2$Te$_3$ thin films, we comb...
cond-mat_mes-hall
Vorticity and quantum turbulence in the merging of superfluid Helium nanodroplets: We have studied the merging of two $^4$He droplets at zero temperature, caused by their Van der Waals mutual attraction. During the early stages of the merging, density structures appear which closely match the experimental observation...
cond-mat_mes-hall
Voltage switching and domain relocation in semiconductor superlattices: A numerical study of domain wall relocation during voltage switching with different ramping times is presented for weakly coupled, doped semiconductor superlattices exhibiting multistable domain formation in the first plateau of their current-volta...
cond-mat_mes-hall
Metastability and dynamics in remanent states of square artificial spin ice with long-range dipole interactions: After removal of an applied magnetic field, artificial square spin ice can be left in a metastable remanent state, with nonzero residual magnetization and excess energy above the ground state. Using a mode...
cond-mat_mes-hall
Periodic negative differential conductance in a single metallic nano-cage: We report a bi-polar multiple periodic negative differential conductance (NDC) effect on a single cage-shaped Ru nanoparticle measured using scanning tunneling spectroscopy. This phenomenon is assigned to the unique multiply-connected cage arc...
cond-mat_mes-hall
Thermally-Activated Phase Slips in Superfluid Spin Transport in Magnetic Wires: We theoretically study thermally-activated phase slips in superfluid spin transport in easy-plane magnetic wires within the stochastic Landau-Lifshitz-Gilbert phenomenology, which runs parallel to the Langer-Ambegaokar-McCumber-Halperin t...
cond-mat_mes-hall
Critical current of spin transfer torque-driven magnetization dynamics in magnetic multilayers: The critical current of the spin transfer torque-driven magnetization dynamics was studied by taking into account both spin pumping and the finite penetration depth of the transverse spin current. We successfully reproduce...
cond-mat_mes-hall
Non-equilibrium theory for strongly coupled quantum dot with arbitrary on-site correlation strength: An analytical expression for the current through a single level quantum dot for arbitrary strength of the on-site electron-electron interaction is derived beyond standard mean-field theory. By describing the localised...
cond-mat_mes-hall
Spin-Torque and Spin-Hall Nano-Oscillators: This paper reviews the state of the art in spin-torque and spin Hall effect driven nano-oscillators. After a brief introduction to the underlying physics, the authors discuss different implementations of these oscillators, their functional properties in terms of frequency ran...
cond-mat_mes-hall
Persistent currents and magnetic flux trapping in fragments of carbon deposits containing multiwalled nanotubes: It is found that the magnetization curves of samples of fragments of cathode carbon deposits with a high content of multiwalled nanotubes exhibit a pronounced irreversible character, attesting to the induc...
cond-mat_mes-hall
Geometrical Effect Explains Graphene Membrane Stiffening at Finite Vacancy Concentrations: The presence of defects such as vacancies in solids has prominent effects on their mechanical properties. It not only modifies the stiffness and strength of materials, but also changes their morphologies. The latter effect is e...
cond-mat_mes-hall
The Atomic and Electronic structure of 0° and 60° grain boundaries in MoS2: We have investigated atomic and electronic structure of grain boundaries in monolayer MoS2, where relative angles between two different grains are 0 and 60 degree. The grain boundaries with specific relative angle have been formed with chemic...
cond-mat_mes-hall
On the Relevance of Disorder for Dirac Fermions with Imaginary Vector Potential: We consider the effects of disorder in a Dirac-like Hamiltonian. In order to use conformal perturbation theory, we argue that one should consider disorder in an imaginary vector potential. This affects significantly the signs of the lowe...
cond-mat_mes-hall
Kinetic Monte Carlo Approach to Non-equilibrium Bosonic Systems: We consider the use of a Kinetic Monte Carlo approach for the description of non-equilibrium bosonic systems, taking non-resonantly excited exciton-polariton condensates and bosonic cascade lasers as examples. In the former case, the considered approach a...
cond-mat_mes-hall
Non-adiabatic current generation in a finite width semiconductor ring: We consider a model of a semiconductor quantum ring of finite width in a constant perpendicular magnetic field. We show how a current of the same order as the persistent current can be generated non-adiabatically by a short intensive pulse in the Te...
cond-mat_mes-hall
Quantum gates by periodic driving: Topological quantum computation has been extensively studied due to its robustness against decoherence. A conventional way to realize it is by adiabatic operations---it requires relatively long time to accomplish so that the speed of quantum computation slows down. In this work, we pr...
cond-mat_mes-hall
Microscopic theory of quantum-transport phenomena in mesoscopic systems: A Monte Carlo approach: A theoretical investigation of quantum-transport phenomena in mesoscopic systems is presented. In particular, a generalization to ``open systems'' of the well-known semiconductor Bloch equations is proposed. The presence ...
cond-mat_mes-hall
Voltage-Controlled Low-Energy Switching of Nanomagnets through Ruderman-Kittel-Kasuya-Yosida Interactions for Magnetoelectric Device Applications: In this letter, we consider through simulation Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions between nanomagnets sitting on a conductive surface, and voltage-control...
cond-mat_mes-hall
Photon Absorption of Two-dimensional Nonsymmorphic Dirac Semimetals: Two-dimensional Dirac semimetals have attracted much attention because of their linear energy dispersion and non-trivial Berry phase. Graphene-like 2D Dirac materials are gapless only within certain approximations, e.g., if spin-orbit coupling (SOC) i...
cond-mat_mes-hall
Surface segregation in nanoparticles from first principles: FePt nanoparticles are known to exhibit reduced L1$_0$ order with decreasing particle size. The reduction in order reduces the magnetic anisotropy and the thermal stability of the direction of magnetization of the particle. The phenomenon is addressed by inves...
cond-mat_mes-hall
Deterministic formation of highly coherent nitrogen-vacancy centers using a focused electron irradiation technique: We demonstrate fully three-dimensional and patterned localization of nitrogen-vacancy (NV) centers in diamond with coherence times in excess of 1 ms. Nitrogen {\delta}-doping during CVD diamond growth v...
cond-mat_mes-hall
Magneto-Electric Effect for Multiferroic Thin Film by Monte Carlo Simulation: Magneto-electric effect in a multiferroic heterostructure film, i.e. a coupled ferromagnetic-ferroelectric thin film, has been investigated through the use of the Metropolis algorithm in Monte Carlo simulations. A classical Heisenberg model...
cond-mat_mes-hall
Effect of laser on thermopower of chiral carbon nanotube: An investigation of laser stimulated thermopower in chiral CNT is presented. The thermopower of a chiral CNT is calculated using a tractable analytical approach. This is done by solving the Boltzmann kinetic equation with energy dispersion relation obtained in t...
cond-mat_mes-hall
Excited State Quantum Couplings and Optical Switching of an Artificial Molecule: We optically probe the spectrum of ground and excited state transitions of an individual, electrically tunable self-assembled quantum dot molecule. Photocurrent absorption measurements show that the spatially direct neutral exciton trans...
cond-mat_mes-hall
Fano resonance in Raman scattering of graphene: Fano resonances and their strong doping dependence are observed in Raman scattering of single-layer graphene (SLG). As the Fermi level is varied by a back-gate bias, the Raman G band of SLG exhibits an asymmetric line shape near the charge neutrality point as a manifestat...
cond-mat_mes-hall
Electron transport in semiconducting carbon nanotubes with hetero-metallic contacts: We present an atomistic self-consistent study of the electronic and transport properties of semiconducting carbon nanotube in contact with metal electrodes of different work functions, which shows simultaneous electron and hole dopin...
cond-mat_mes-hall
Using nonlocal surface transport to identify the axion insulator: The axion is a hypothetical but experimentally undetected particle. Recently, the antiferromagnetic topological insulator MnBi$_2$Te$_4$ has been predicted to host the axion insulator, but the experimental evidence remains elusive. Specifically, the axio...
cond-mat_mes-hall
Quantum Confinement in Si and Ge Nanostructures: We apply perturbative effective mass theory as a broadly applicable theoretical model for quantum confinement (QC) in all Si and Ge nanostructures including quantum wells (QWs), wires (Q-wires) and dots (QDs). Within the limits of strong, medium, and weak QC, valence and...
cond-mat_mes-hall
Dark Exciton Giant Rabi Oscillations with no External Magnetic Field: Multi-phonon physics is an emerging field that serves as a test bed for fundamental quantum physics and several applications in metrology, on-chip communication, among others. Quantum acoustic cavities or resonators are devices that are being used to...
cond-mat_mes-hall
Linear-response magnetoresistance effects in chiral systems: The chirality-induced spin selectivity (CISS) effect enables the detection of chirality as electrical charge signals. It is often studied using a two-terminal circuit geometry where a ferromagnet is connected to a chiral component, and a change of electrical ...
cond-mat_mes-hall
Band geometry from position-momentum duality at topological band crossings: We show that the position-momentum duality offers a transparent interpretation of the band geometry at the topological band crossings. Under this duality, the band geometry with Berry connection is dual to the free-electron motion under gauge...
cond-mat_mes-hall
Coherent tunnelling across a quantum point contact in the quantum Hall regime: The unique properties of quantum Hall devices arise from the ideal one-dimensional edge states that form in a two-dimensional electron system at high magnetic field. Tunnelling between edge states across a quantum point contact (QPC) has a...
cond-mat_mes-hall
Electrical Transport Across an Individual Magnetic Domain Wall in (Ga,Mn)As Microdevices: Recent studies demonstrate that an individual magnetic domain wall (DW) can be trapped and reproducibly positioned within multiterminal (Ga,Mn)As microdevices. The electrical resistance obtained from such measurements is found t...
cond-mat_mes-hall
2D MoS2-Graphene-based multilayer van der Waals heterostructures: Enhanced charge transfer and optical absorption, and electric-field tunable Dirac point and band gap: Multilayer van der Waals (vdWs) heterostructures assembled by diverse atomically thin layers have demonstrated a wide range of fascinating phenomena...
cond-mat_mes-hall
Positive longitudinal spin magnetoconductivity in $\mathbb{Z}_{2}$ topological Dirac semimetals: Recently, a class of Dirac semimetals, such as \textrm{Na}$_{\mathrm{3}}% $\textrm{Bi} and \textrm{Cd}$_{\mathrm{2}}$\textrm{As}$_{\mathrm{3}}$, are discovered to carry $\mathbb{Z}_{2}$ monopole charges. We present an exp...
cond-mat_mes-hall
Andreev-Coulomb Drag in Coupled Quantum Dots: The Coulomb drag effect has been observed as a tiny current induced by both electron-hole asymmetry and interactions in normal coupled quantum dot devices. In the present work we show that the effect can be boosted by replacing one of the normal electrodes by a superconduct...
cond-mat_mes-hall
Effects of mechanical rotation on spin currents: We study the Pauli--Schr\"odinger equation in a uniformly rotating frame of reference to describe a coupling of spins and mechanical rotations. The explicit form of the spin-orbit interaction (SOI) with the inertial effects due to the mechanical rotation is presented. We...
cond-mat_mes-hall
Tunable terahertz radiation from graphene induced by moving electrons: Based on a structure consisting of a single graphene layer situated on a periodic dielectric grating, we show theoretically that intense terahertz (THz) radiations can be generated by an electron bunch moving atop the graphene layer. The underlying ...
cond-mat_mes-hall
Metamorphosis of Andreev bound states into Majorana bound states in pristine nanowires: We show theoretically that in the generic finite chemical potential situation, the clean superconducting spin-orbit-coupled nanowire has two distinct nontopological regimes as a function of Zeeman splitting (below the topological ...
cond-mat_mes-hall
Cyclotron resonance of single valley Dirac fermions in gapless HgTe quantum well: We report on Landau level spectroscopy studies of two HgTe quantum wells (QWs) near or at the critical well thickness, where the band gap vanishes. In magnetic fields up to $B$=16T, oriented perpendicular to the QW plane, we observe a $...
cond-mat_mes-hall
Quantum anomalies in nodal line semimetals: Topological semimetals is a new class of condensed matter systems with nontrivial electronic structure topology. Their unusual observable properties may often be understood in terms of quantum anomalies. In particular, Weyl and Dirac semimetals, which have point band touching...
cond-mat_mes-hall
Magnetotransport properties of granular oxide-segregated CoPtCr films for applications in future magnetic memory technology: Magnetotransport properties of granular oxide-segregated CoPtCr films were studied on both macroscopic and microscopic length scales by performing bulk and point-contact magnetoresistance measu...
cond-mat_mes-hall
Generating surface states in a Weyl semi-metal by applying electromagnetic radiation: We show that the application of circularly polarized electromagnetic radiation on the surface of a Weyl semi-metal can generate states at that surface. These states can be characterized by their surface momentum. The Floquet eigenva...
cond-mat_mes-hall
Extending the spin excitation lifetime of a magnetic molecule on a proximitized superconductor: Magnetic molecules deposited on surfaces are a promising platform to individually address and manipulate spins. Long spin excitation lifetimes are necessary to utilize them in quantum information processing and data storag...
cond-mat_mes-hall
Valley-selective exciton bistability in a suspended monolayer semiconductor: We demonstrate robust power- and wavelength-dependent optical bistability in fully suspended monolayers of WSe2 near the exciton resonance. Bistability has been achieved under continuous-wave optical excitation at an intensity level of 10^3 ...
cond-mat_mes-hall
Overlapping Andreev states in semiconducting nanowires: competition of 1D and 3D propagation: The recent proposals of devices with overlapping Andreev bound states (ABS) open up the opportunities to control and fine-tune their spectrum, that can be used in various applications. In this Article, we study the ABS in a ...
cond-mat_mes-hall
Anomalous Thermal Transport in Quantum Wires: We study thermal transport in a one-dimensional quantum wire, connected to reservoirs. Despite of the absence of electron backscattering, interactions in the wire strongly influence thermal transport. Electrons propagate with unitary transmission through the wire and electr...
cond-mat_mes-hall
Transport through quantum spin Hall insulator/metal junctions in graphene ribbons: Quantum spin Hall insulator/metal interfaces are formed in graphene ribbons with intrinsic spin-orbit coupling by selectively doping two regions creating a potential step. For a clean graphene ribbon, the transmission of the topologica...
cond-mat_mes-hall
Switching 2D Magnetic States via Pressure Tuning of Layer Stacking: The physical properties of two-dimensional van der Waals (2D vdW) crystals depend sensitively on the interlayer coupling, which is intimately connected to the stacking arrangement and the interlayer spacing. For example, simply changing the twist angle...
cond-mat_mes-hall
Tunable strong coupling of mechanical resonance between spatially separated FePS$_3$ nanodrums: Coupled nanomechanical resonators made of two-dimensional materials are promising for processing information with mechanical modes. However, the challenge for these types of systems is to control the coupling. Here, we dem...
cond-mat_mes-hall
Polarization bistability and resultant spin rings in semiconductor microcavities: The transmission of a pump laser resonant with the lower polariton branch of a semiconductor microcavity is shown to be highly dependent on the degree of circular polarization of the pump. Spin dependent anisotropy of polariton-polarito...
cond-mat_mes-hall
Moderate bandgap and high carrier mobility simultaneously realized in bilayer silicene by oxidation: Semiconductors simultaneously possessing high carrier mobility, moderate bandgap, and ambient environment stability are so important for the modern industry, and Si-based semiconducting materials can match well with t...
cond-mat_mes-hall
Full Counting Statistics of a Non-adiabatic Electron Pump: Non-adiabatic charge pumping through a single-level quantum dot with periodically modulated parameters is studied theoretically. By means of a quantum-master-equation approach the full counting statistics of the system is obtained. We find a trinomial-probabili...
cond-mat_mes-hall
Step-like features on caloric effects of graphenes: We considered a graphene nano-ribbon with a longitudinal electric field (along $x$ direction) and a transversal magnetic field (along $z$ direction), and then observe (i) the electrocaloric effect ruled by an applied magnetic field and (ii) the magnetocaloric effect r...
cond-mat_mes-hall
Size-dependent spatial magnetization profile of manganese-zinc ferrite Mn0.2Zn0.2Fe2.6O4 nanoparticles: We report the results of an unpolarized small-angle neutron scattering (SANS) study on Mn-Zn ferrite (MZFO) magnetic nanoparticles with the aim to elucidate the interplay between their particle size and the magneti...
cond-mat_mes-hall
Near-field infrared nano-spectroscopy of surface phonon-polariton resonances: We present combined experimental and numerical work on light-matter interactions at nanometer length scales. We report novel numerical simulations of near-field infrared nanospectroscopy that consider, for the first time, detailed tip geome...
cond-mat_mes-hall
Instanton Approach to Josephson Tunneling between Trapped Condensates: An instanton method is proposed to investigate the quantum tunneling between two weakly-linked Bose-Einstein condensates confined in double-well potential traps. We point out some intrinsic pathologies in the earlier treatments of other authors and ...
cond-mat_mes-hall
Universal dephasing in a chiral 1D interacting fermion system: We consider dephasing by interactions in a one-dimensional chiral fermion system (e.g. a Quantum Hall edge state). For finite-range interactions, we calculate the spatial decay of the Green's function at fixed energy, which sets the contrast in a Mach-Zehnd...
cond-mat_mes-hall
Acoustic plasmons in graphene sandwiched between two metallic slabs: We study the effect of two metallic slabs on the collective dynamics of electrons in graphene positioned between the two slabs. We show that if the slabs are perfect conductors the plasmons of graphene display a linear dispersion relation. The velocit...
cond-mat_mes-hall
Flat bands and chiral optical response of moiré insulators: We present a low-energy model describing the reconstruction of the electronic spectrum in twisted bilayers of honeycomb crystals with broken sublattice symmetry. The resulting moir\'e patterns are classified into two families with different symmetry. In both c...
cond-mat_mes-hall
Field-effect tunneling transistor based on vertical graphene heterostructures: We report a bipolar field effect tunneling transistor that exploits to advantage the low density of states in graphene and its one atomic layer thickness. Our proof-of-concept devices are graphene heterostructures with atomically thin boro...
cond-mat_mes-hall
Interference of diffusing photons and level crossing spectroscopy: We show that a new interference effect appears in the intensity fluctuations of photons multiply scattered by an atomic gas of large optical depth b. This interference occurs only for scattering atoms that are Zeeman degenerate and it leads to a deviati...
cond-mat_mes-hall
Disorder-mediated Kondo effect in graphene: We study the emergence of strongly correlated states and Kondo physics in disordered graphene. Diluted short range disorder gives rise to localized midgap states at the vicinity of the system charge neutrality point. We show that long-range disorder, ubiquitous in graphene, a...
cond-mat_mes-hall
Giant excitonic magneto-optical Faraday rotation in single semimagnetic CdTe/Cd_{1-x}Mn_{x}Te quantum ring: Magnetic tuning of the bound exciton states and corresponding giant Zeeman splitting (GZS) between {\sigma}^{+} and {\sigma}^{-} excitonic transitions in CdTe/Cd_{1-x}Mn_{x}Te quantum ring has been investigated...
cond-mat_mes-hall
Topological qubits in graphenelike systems: The fermion-doubling problem can be an obstacle to getting half-a-qubit in two-dimensional fermionic tight-binding models in the form of Majorana zero modes bound to the core of superconducting vortices. We argue that the number of such Majorana zero modes is determined by a ...
cond-mat_mes-hall
Novel mechanisms to enhance the capacitance beyond the classical limits in capacitors with free-electron-like electrodes: The so-called negative electron compressibility refers to the lowering of the chemical potential of a metallic system when the carrier density increases. This effect has often been invoked in the ...
cond-mat_mes-hall
Valley degeneracy in biaxially strained aluminum arsenide quantum wells: This paper details a complete formalism for calculating electron subband energy and degeneracy in strained multi-valley quantum wells grown along any orientation with explicit results for the AlAs quantum well case. A standardized rotation matrix ...
cond-mat_mes-hall
Kinetics of Exciton Emission Patterns and Carrier Transport: We report on the measurements of the kinetics of expanding and collapsing rings in the exciton emission pattern. The rings are found to preserve their integrity during expansion and collapse, indicating that the observed kinetics is controlled by charge carri...
cond-mat_mes-hall
Heat transport in harmonic lattices: We work out the non-equilibrium steady state properties of a harmonic lattice which is connected to heat reservoirs at different temperatures. The heat reservoirs are themselves modeled as harmonic systems. Our approach is to write quantum Langevin equations for the system and solve...
cond-mat_mes-hall
Scaling for rectification of bipolar nanopores as a function of a modified Dukhin number: the case of 1:1 electrolytes: The scaling behavior for the rectification of bipolar nanopores is studied using the Nernst-Planck equation coupled to the Local Equilibrium Monte Carlo method. The bipolar nanopore's wall carries $...
cond-mat_mes-hall
Scaling properties of induced density of chiral and non-chiral Dirac fermions in magnetic fields: We find that a repulsive potential of graphene in the presence of a magnetic field has bound states that are peaked inside the barrier with tails extending over \ell(N + 1), where \ell and N are the magnetic length and L...
cond-mat_mes-hall
Minimal model for charge transfer excitons at the dielectric interface: Theoretical description of the charge transfer (CT) exciton across the donor-acceptor interface without the use of a completely localized hole (or electron) is a challenge in the field of organic solar cells. We calculate the total wavefunction of ...
cond-mat_mes-hall
Robustness of the quantum Hall effect, sample size versus sample topology, and quality control management of III-V molecular beam epitaxy: We measure the IQHE on macroscopic (1.5cm x 1.5cm) "quick 'n' dirty" prepared III-V heterostructure samples with van der Pauw and modified Corbino geometries at 1.3 K. We compare ...
cond-mat_mes-hall
Realization of a Laughlin quasiparticle interferometer: Observation of fractional statistics: In two dimensions, the laws of physics permit existence of anyons, particles with fractional statistics which is neither Fermi nor Bose. That is, upon exchange of two such particles, the quantum state of a system acquires a ...
cond-mat_mes-hall
Double refraction and spin splitter in a normal-hexagonal semiconductor junction: In analogy with light refraction at optical boundary, ballistic electrons also undergo refraction when propagate across a semiconductor junction. Establishing a negative refractive index in conventional optical materials is difficult, b...
cond-mat_mes-hall
Electron quantum dynamics in closed and open potentials at high magnetic fields: Quantization and lifetime effects unified by semicoherent states: We have developed a Green's function formalism based on the use of an overcomplete semicoherent basis of vortex states, specially devoted to the study of the Hamiltonian q...
cond-mat_mes-hall
Generating quantizing pseudomagnetic fields by bending graphene ribbons: We analyze the mechanical deformations that are required to create uniform pseudomagnetic fields in graphene. It is shown that, if a ribbon is bent in-plane into a circular arc, this can lead to fields exceeding 10T, which is sufficient for the ob...
cond-mat_mes-hall
Dynamic frequency dependence of bias activated negative capacitance in semiconductor diodes under high forward bias: We observed qualitatively dissimilar frequency dependence of negative capacitive response under high charge injection in two sets of junction diodes which are functionally different from each other i.e...
cond-mat_mes-hall
Weak antilocalization beyond the fully diffusive regime in Pb1-xSnxSe topological quantum wells: We report the measurements and analysis of weak antilocalization (WAL) in Pb1-xSnxSe topological quantum wells in a new regime where the elastic scattering length is larger than the magnetic length. We achieve this regime...
cond-mat_mes-hall
Using single quantum states as spin filters to study spin polarization in ferromagnets: By measuring electron tunneling between a ferromagnet and individual energy levels in an aluminum quantum dot, we show how spin-resolved quantum states can be used as filters to determine spin-dependent tunneling rates. We also ob...
cond-mat_mes-hall
Quantum properties of a strongly driven Josephson junction: A Josephson junction embedded in a dissipative circuit can be externally driven to induce nonlinear dynamics of its phase. Classically, under sufficiently strong driving and weak damping, dynamic multi-stability emerges associated with dynamical bifurcations s...
cond-mat_mes-hall
Spatiotemporal spin fluctuations caused by spin-orbit-coupled Brownian motion: We develop a theory of thermal fluctuations of spin density emerging in a two-dimensional electron gas. The spin fluctuations probed at spatially separated spots of the sample are correlated due to Brownian motion of electrons and spin-obi...
cond-mat_mes-hall
Ab initio simulation of the structure and transport properties of zirconium and ferromagnetic cobalt contacts on the two-dimensional semiconductor WS_2: Using density-functional theory calculations, the atomic and electronic structure of single-layer WS_2 attached to Zr and Co contacts are determined. Both metals f...
cond-mat_mes-hall
Large-Scale Schrödinger-Cat States and Majorana Bound States in Coupled Circuit-QED Systems: We have studied the low-lying excitations of a chain of coupled circuit-QED systems, and report several intriguing properties of its two nearly degenerate ground states. The ground states are Schr\"odinger cat states at a tru...
cond-mat_mes-hall
High Mobility Free-Standing InSb Nanoflags Grown On InP Nanowire Stems For Quantum Devices: High quality heteroepitaxial two-dimensional (2D) InSb layers are very difficult to realize owing to the large lattice mismatch with other widespread semiconductor substrates. A way around this problem is to grow free-standing...
cond-mat_mes-hall
Thermally-Activated Phase Slips in Superfluid Spin Transport in Magnetic Wires: We theoretically study thermally-activated phase slips in superfluid spin transport in easy-plane magnetic wires within the stochastic Landau-Lifshitz-Gilbert phenomenology, which runs parallel to the Langer-Ambegaokar-McCumber-Halperin t...
cond-mat_mes-hall
Multiphoton excitation and high harmonic generation in rectangular graphene quantum dot: The multiphoton excitation and high harmonic generation (HHG) processes are considered using the microscopic quantum theory of nonlinear interaction of strong coherent electromagnetic (EM) radiation with rectangular graphene quan...
cond-mat_mes-hall
Commensurate and incommensurate double moiré interference in twisted trilayer graphene: Twisted graphene multi-layers have been recently demonstrated to share several correlation-driven behaviours with twisted bilayer graphene. In general, the van Hove singularities (VHSs) can be used as a proxy of the tendency for c...
cond-mat_mes-hall
Anisotropic 2D materials for tunable hyperbolic plasmonics: Motivated by the recent emergence of a new class of anisotropic 2D materials, we examine their electromagnetic modes and demonstrate that a broad class of the materials can host highly directional hyperbolic plasmons. Their propagation direction can be manipul...
cond-mat_mes-hall
Resonant Coherent Phonon Generation in Single-Walled Carbon Nanotubes through Near-Band-Edge Excitation: We have observed large-amplitude coherent phonon oscillations of radial breathing modes (RBMs) in single-walled carbon nanotubes excited through the lowest-energy (E11) interband transitions. In contrast to the pr...
cond-mat_mes-hall
Quantum Hall Effect in a Graphene p-n Junction: We report on the fabrication and transport studies of a single-layer graphene p-n junction. Carrier type and density in two adjacent regions are individually controlled by electrostatic gating using a local top gate and a global back gate. A functionalized Al203 oxide tha...
cond-mat_mes-hall
The dynamical bulk boundary correspondence and dynamical quantum phase transitions in the Benalcazar-Bernevig-Hughes model: In this article we demonstrate that dynamical quantum phase transitions occur for an exemplary higher order topological insulator, the Benalcazar-Bernevig-Hughes model, following quenches across...
cond-mat_mes-hall
Robust Type-II Weyl Semimetal Phase in Transition Metal Diphosphides XP$_2$ (X = Mo, W): The recently discovered type-II Weyl points appear at the boundary between electron and hole pockets. Type-II Weyl semimetals that host such points are predicted to exhibit a new type of chiral anomaly and possess thermodynamic p...
cond-mat_mes-hall