Latest in cond-mat.mtrl-sci

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Highly anisotropic interlayer magnetoresistance in ZrSiS nodal-line Dirac semimetalApr 22 2019We instigate the angle-dependent magnetoresistance (AMR) of the layered nodal-line Dirac semimetal ZrSiS for the in-plane and out-of-plane current directions. This material has recently revealed an intriguing butterfly-shaped in-plane AMR that is not ... More
Unusual magnetotransport in Al6ReApr 22 2019Since very few Type-I superconductors are known and most are elemental superconductors, there are very few experimental platforms where the interaction between Type-I superconductivity and topologically nontrivial band structure can be probed. The rhenium ... More
First principles prediction of the solar cell efficiency of chalcopyrite materials AgMX2 (M=In,Al; X=S, Se,Te)Apr 22 2019Using the Spectroscopic Limited Maximum Efficiency, and Shockley and Queisser predictor models, we compute the solar efficiency of the chalcopyrites AgMX2(M=In,Al;X=S,Se,Te). The results presented are based on the estimation of the electronic and optical ... More
One Dimensional Nearly Free Electron States in BoropheneApr 22 2019Two-dimensional boron (borophene) is featured by its structural polymorphs and distinct in-plane anisotropy, opening opportunities to achieve tailored electronic properties by intermixing different phases. Here, using scanning tunneling spectroscopy combined ... More
Ab initio study of phosphorus effect on vacancy-mediated process in nickel alloys - an insight into Ni2Cr orderingApr 22 2019The development of long range order in nickel-chromium alloys is of great technological interest but the kinetics and mechanisms of the transformation are poorly understood. The present research utilizes a combined computational and experimental approach ... More
Flux effects in precipitation under irradiation - Simulation of Fe-Cr alloysApr 21 2019Radiation-enhanced precipitation of Cr-rich {\alpha}' in irradiated Fe-Cr alloys, which results in hardening and embrittlement, depends on the irradiating particle and the displacement per atom (dpa) rate. Here, we utilize a Cahn-Hilliard phase-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
Visualizing the Effect of an Electrostatic Gate with Angle-Resolved Photoemission SpectroscopyApr 20 2019Electrostatic gating is pervasive in materials science, yet its effects on the electronic band structure of materials has never been revealed directly by angle-resolved photoemission spectroscopy (ARPES), the technique of choice to non-invasively probe ... More
Tunable Berry Curvature Through Magnetic Phase Competition in a Topological Kagome MagnetApr 19 2019Magnetic topological phases of quantum matter are an emerging frontier in physics and material science. Along these lines, several kagome magnets have appeared as the most promising platforms. However, the magnetic nature of these materials in the presence ... More
Superlattice-induced ferroelectricity in charge-ordered La$_{1/3}$Sr$_{2/3}$FeO$_{3}$Apr 19 2019Charge-order-driven ferroelectrics are an emerging class of functional materials, distinct from conventional ferroelectrics, where electron-dominated switching can occur at high frequency. Despite their promise, only a few systems exhibiting this behavior ... More
Synthesis, properties and thermal decomposition of the Ta4AlC3 MAX phaseApr 19 2019The present work describes a synthesis route for bulk Ta4AlC3 MAX phase ceramics with high phase purity. Pressure assisted densification was achieved by both hot pressing and spark plasma sintering of tantalum hydride, aluminium and carbon powder mixtures ... More
Crystal plasticity analysis of deformation anisotropy of lamellar TiAl alloy: 3D microstructure-based modelling and in-situ micro-compressionApr 19 2019Detailed microstructure characterisation and in-situ micropillar compression were coupled with crystal plasticity-based finite element modelling (CP-FEM) to study the micro-mechanisms of plastic anisotropy in lamellar TiAl alloys. The consideration of ... More
Theoretical study of phase transitions in Sb2S3, Bi2S3 and Sb2Se3 under compressionApr 19 2019We report a theoretical study of Sb2S3, Sb2Se3 and Bi2S3 sesquichalcogenides at hydrostatic pressures up to 60 GPa. We explore the possibility that the R-3m, C2/m, C2/c and Im-3m phases observed in sesquichalcogenides with heavier cations, viz. Bi2Se3, ... More
Epitaxial Stabilization of $\mathrm{Ge_{1-x}Sn_x}$ AlloysApr 19 2019The thermodynamic stability of $\mathrm{Ge_{1-x}Sn_x}$ alloys is investigated across the full composition range by employing density functional theory (DFT) in conjunction with the cluster expansion formalism (CE). Configurational, vibrational, and electronic ... More
Heterometallic Metal-Organic Frameworks of MOF-5 and UiO-66 Families: Insight from Computational ChemistryApr 19 2019We study the energetic stability and structural features of bimetallic metal-organic frameworks. Such heterometallic MOFs, which can result from partial substitutions between two types of cations, can have specific physical or chemical properties used ... More
Spin wave dispersion of 3d ferromagnets based on QSGW calculationsApr 19 2019We have calculated spin wave (SW) dispersion by combining the quasi-particle self-consistent $GW$ (QSGW) and linear response method for transverse dynamical susceptibility $\chi^{+-}({\bf q},\omega)$. We compared the QSGW and the local density approximation ... More
Quantifying the search for solid Li-ion electrolyte materials by anion: a data-driven perspectiveApr 18 2019We compile data and machine learned models of solid Li-ion electrolyte performance to assess the state of materials discovery efforts and build new insights for future efforts. Candidate electrolyte materials must satisfy several requirements, chief among ... More
High Entropy Alloys Mined From Phase DiagramsApr 18 2019High entropy alloys (HEA) show promise as a new type of high-performance structural material. Their vast degrees of freedom provide for extensive opportunities to design alloys with tailored properties. However, the compositional complexities of HEAs ... More
DScribe: Library of Descriptors for Machine Learning in Materials ScienceApr 18 2019DScribe is a software package for machine learning that provides popular feature transformations ("descriptors") for atomistic materials simulations. DScribe accelerates the application of machine learning for atomistic property prediction by providing ... More
Bi2Te3/Sb2Te3 Heterojunction and Thermophotovoltaic Cells Absorbing the Radiation from Room-temperature SurroundingsApr 18 2019The thermophotovoltaic cells which can convert the infrared radiation from room-temperature surroundings into electricity are of significance due to their potential applications in many fields. In this work, narrow bandgap Bi2Te3/Sb2Te3 thin film thermophotovoltaic ... More
$\mathrm{BaAs_3}$: A narrow gap 2D semiconductor with vacancy-induced semiconductor-metal transitionApr 18 2019Searching for novel two-dimensional (2D) materials is highly desired in the field of nanoelectronics. We here propose a new 2D crystal barium tri-arsenide ($\mathrm{BaAs_3}$) with a series of encouraging functionalities. Being kinetically and thermally ... More
Electronic and optical excitations of two-dimensional ZrS$_2$ and HfS$_2$ and their heterostructureApr 18 2019In a first-principles study based on density-functional theory and many-body perturbation theory we investigate the electronic properties and the optical excitations of ZrS$_2$ and HfS$_2$ monolayers and their van der Waals heterostructure. Both materials ... More
Diffusion properties of electrons in GaN crystals subjected to electric and magnetic fieldsApr 18 2019We studied the diffusion coefficient of hot electrons of GaN crystals in moderate electric (1...10 kV/cm) and magnetic (1...4 T) fields. Two configurations, parallel and crossed fields, are analysed. The study was carried out for compensated bulk-like ... 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
Water-based and Inkjet Printable Inks made by Electrochemically Exfoliated GrapheneApr 18 2019Inkjet printable graphene inks are very attractive for applications in flexible and foldable electronics, such as wearable electronics and the Internet of Things. However, the ink preparation is still very time consuming as high concentrations can be ... 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
Suppression of long range magnetic ordering and electrical conduction in Y$_{1.7}$Bi$_{0.3}$Ir$_2$O$_7$ thin filmApr 18 2019We find that the long-range magnetic ordering is absent and electrical conduction suppressed in Y$_{1.7}$Bi$_{0.3}$Ir$_2$O$_7$/YSZ(100) thin film prepared by pulsed laser deposition. The sharp down-turn of inverse magnetic susceptibility X-1(T) from the ... More
Anomalous conduction band fluctuation in silicon carbide metal-oxide-semiconductor structures revealed by electrical characterization of field effect transistors combined with self-consistent numerical calculationsApr 18 2019We determined the interface state density ($D_{\rm it}$) distributions in the vicinity of the conduction band edge in silicon carbide (SiC) metal-oxide-semiconductor (MOS) structures by reproducing the experimental current-voltage characteristics of MOS ... More
Quantitative exploration of the bright and dark exciton landscape and fine structure of MoS2 (using G0W0-BSE)Apr 18 2019Spectral ordering between dark and bright excitons in transition metal dichalcogenides is of increasing interest for optoelectronic applications. However, little is known about dark exciton energies and their binding energies. We report the exciton landscape ... More
Scaling-up atomically thin coplanar semiconductor-metal circuitry via phase engineered chemical assemblyApr 18 2019Two-dimensional (2D) layered semiconductors, with their ultimate atomic thickness, have shown promise to scale down transistors for modern integrated circuitry. However, the electrical contacts that connect these materials with external bulky metals are ... More
Revisiting the fragile-to-strong crossover in metallic glass-forming liquids: application to Cu$_x$Zr$_x$Al$_{100-2x}$Apr 17 2019The fragile-to-strong crossover seems to be a general feature of metallic glass-forming liquids. Here, we study the behavior of shear viscosity, diffusion coefficient and vibrational density of states for Cu$_x$Zr$_x$Al$_{100-2x}$ alloy through molecular ... More
High-angular resolution electron backscatter diffraction as a new tool for mapping lattice distortion in geological mineralsApr 17 2019Analysis of distortions of the crystal lattice within individual mineral grains is central to the investigation of microscale processes that control and record tectonic events. These distortions are generally combinations of lattice rotations and elastic ... More
Gas-phase synthesis of carbon nanotube-graphene heterostructuresApr 17 2019Graphene and carbon nanotubes (CNTs) share the same atomic structure of hexagonal carbon lattice. Yet, their synthesis differs in many aspects, including the shape and size of the catalyst. Here, we demonstrate a floating-catalyst chemical vapor deposition ... 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
Melting curve of elemental zirconiumApr 17 2019Melting experiments require rapid data acquisition due to instabilities of the molten sample and optical drifting due to the high required laser power. In this work, the melting curve of zirconium has been determined for the first time up to 80 GPa and ... 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
Effect of lattice shrinking on the migration of water within zeolite LTAApr 17 2019Water adsorption within zeolites of the Linde Type A (LTA) structure plays an important role in processes of water removal from solvents. For this purpose, knowing in which adsorption sites water is preferably found is of interest. In this paper, the ... More
Toughening in a nacre-like soft-hard layered structure due to weak nonlinearity in the soft layerApr 17 2019Recently, it has been found experimentally that hydrated nacre exhibits a nonlinear mechanical response. While mechanical nonlinearity has been shown to be important in other biological structures, such as spider webs, the implications of mechanical nonlinearity ... More
Structural, electronic properties and the features of chemical bonding in layered 1111-oxyarsenides LaRhAsO and LaIrAsO: ab initio modelingApr 17 2019The comparative study of structural, electronic properties, topology of the Fermi surface, and the features of chemical bonding in layered 1111-oxyarsenides LaRhAsO and LaIrAsO has been performed based on the results of ab initio modeling of their electronic ... 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
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
Force induced formation of twisted chiral ribbonsApr 17 2019We study the emergence of helical structures subjected to a stretching force, demonstrating that the force transforms disk-shaped colloidal membranes into twisted chiral ribbons of predetermined handedness. Using an experimental technique that enforces ... More
Strain Control and Layer-Resolved Switching of Negative Capacitance in BaTiO$_3$/SrTiO$_3$ SuperlatticesApr 17 2019Negative capacitance in BaTiO$_3$/SrTiO$_3$ superlattices is investigated by Monte Carlo simulations in an atomistic effective Hamiltonian model, using fluctuation formulas for responses to the local macroscopic field that incorporates depolarizing fields. ... 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
Design and Characterization of Plasmonic Doppler Grating for Azimuthal Angle-resolved Surface Plasmon ResonancesApr 17 2019We present two-dimensional plasmonic Doppler grating (PDG) for broadband azimuthal angle-resolved nanophotonic applications. The PDG consists of a set of non-concentric circular rings mimicking the wavefronts of a moving point source that exhibits Doppler ... 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
Phonon-Phonon Quantum Coherent Coupling in GaAs/AlAs SuperlatticeApr 16 2019We report the observation of quantum coherent coupling at ambient temperature between a zone-center phonon at 330 GHz and two acoustic phonons in GaAs/AlAs superlattice. Fluence-dependent measurement with coherent phonon spectroscopy clearly revealed ... More
COMBIgor: data analysis package for combinatorial materials scienceApr 16 2019Combinatorial experiments involve synthesis of sample libraries with lateral composition gradients requiring spatially-resolved characterization of structure and properties. Due to maturation of combinatorial methods and their successful application in ... More
Electronic structure and phase stability of Yb-filled skutterudite CoSb$_3$ from first principlesApr 16 2019Filling the large voids in the crystal structure of the skutterudite CoSb$_3$ with rattler atoms $R$ provides an avenue for both increasing carrier concentration and disrupting lattice heat transport, leading to impressive thermoelectric performance. ... More
Optical Properties of Bismuth Nanostructures Towards the Ultrathin Film RegimeApr 16 2019Bulk bismuth presents outstanding optical properties, such as a giant infrared refractive index (n near 10) and a negative ultraviolet visible permittivity induced by giant interband electronic transitions. Although such properties are very appealing ... More
Unusual $^{209}$Bi NMR quadrupole effects in topological insulator Bi$_2$Se$_3$Apr 16 2019Three-dimensional topological insulators are an important class of modern materials, and a strong spin-orbit coupling is involved in making the bulk electronic states very different from those near the surface. Bi$_2$Se$_3$ is a model compound, and $^{209}$Bi ... 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
The quest for electronic ferroelectricity in organic charge-transfer crystalsApr 16 2019Organic ferroelectric materials are in demand in the growing field of environmentally friendly, lightweight electronics. Donor-Acceptor charge transfer crystals have been recently proposed as a new class of organic ferroelectrics, which may possess a ... More
Anisotropic exchange Hamiltonian, magnetic phase diagram and domain inversion of Nd$_2$Zr$_2$O$_7$Apr 16 2019We present thermodynamic and neutron scattering measurements on the quantum spin ice candidate Nd$_2$Zr$_2$O$_7$. The parameterization of the anisotropic exchange Hamiltonian is refined based on high-energy-resolution inelastic neutron scattering data ... More
Anisotropic exchange Hamiltonian, magnetic phase diagram and domain inversion of Nd$_2$Zr$_2$O$_7$Apr 16 2019Apr 18 2019We present thermodynamic and neutron scattering measurements on the quantum spin ice candidate Nd$_2$Zr$_2$O$_7$. The parameterization of the anisotropic exchange Hamiltonian is refined based on high-energy-resolution inelastic neutron scattering data ... 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
Strengthening in multi-principal element alloys with local-chemical-order roughened dislocation pathwaysApr 16 2019High-entropy alloys (HEAs) were presumed to have a configurational entropy as high as that of an ideally mixed solid solution (SS) of multiple elements in near-equal proportions. However, enthalpic interactions inevitably render such chemically disordered ... More
A study of $Ce^{3+}$ incorporation in Te-Zn-Nb-La oxide glassesApr 16 2019The effects of Cerium incorporation in a Zinc-Tellurite glass containing Niobium and Lanthanum (TZNL) has been investigated. Samples were produced under air atmosphere and thermal, structural and spectroscopic data was acquired. The doped samples exhibited ... 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
Plasmon Soft Mode in an Organic-Inorganic Hybrid PerovskiteApr 16 2019We report inelastic light scattering from underdamped plasmons in azetidinium lead bromide (AzPbBr3). The plasmons are very strongly temperature dependent and serve as a soft mode for the semiconductor-insulator phase transition near TC {\guillemotright} ... More
Dielectric properties of strained NiO thin filmsApr 16 2019The dielectric properties of NiO thin films grown by pulsed laser deposition have been studied as a function of strain at temperature from 10 to 300 K. Above 150 K, the contribution of space-charge polarization to the dielectric permittivity of NiO films ... More
Random-Organizing Hyperuniform Fluids with Momentum-Conserved ActivationsApr 16 2019Recently, an exotic hyperuniform fluid state was proposed in some non-equilibrium overdamped systems, in which the center of mass conservation (CMC) of local interacting particles was believed to be crucial. In this work, we show that in underdamped systems, ... More
Production and mechanical characterization of graphene micro-ribbonsApr 16 2019Patterning of graphene into micro- and nano-ribbons allows for the tunability in emerging fields such as flexible electronic and optoelectronic devices, and is gaining interest for the production of more efficient reinforcement for composite materials. ... 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
Diffusion-reaction model for positron trapping and annihilation at spherical extended defects and in precipitate--matrix compositesApr 16 2019The exact solution of a diffusion$-$reaction model for the trapping and annihilation of positrons in small extended spherical defects (clusters, voids, small precipitates) with competitive rate-limited trapping in vacancy-type point defects is presented. ... More
Light-Induced Charge Density Wave in LaTe$_3$Apr 16 2019When electrons in a solid are excited with light, they can alter the free energy landscape and access phases of matter that are beyond reach in thermal equilibrium. This accessibility becomes of vast importance in the presence of phase competition, when ... More
Comment on a zero-thermal-quenching phosphorApr 16 2019Kim and co-authors in a recent article reported a phosphor Na3-2xSc2(PO4)3:xEu2+ (NSPO:xEu2+) that did not exhibit thermal quenching (TQ) even up to 200 degree Celsius. The authors suggested that zero-TQ originates from the compensation of emission losses ... More
A phase-field study of elastic stress effects on phase separation in ternary alloysApr 16 2019Most of the commercially important alloys are multicomponent, producing multiphase microstructures as a result of processing. When the coexisting phases are elastically coherent, the elastic interactions between these phases play a major role in the development ... More
Coupling of homogeneous and heterogeneous melting kinetics in polycrystallinesApr 16 2019Melting kinetics of polycrystallines is analyzed on the basis of a new model which explicitly couples homogeneous and heterogeneous melting mechanisms. The distinct feature of this approach lies in its ability to evaluate not only grain-size-distribution ... More
Evolution of interfacial dislocation network during low-stress high temperature creep of particle strengthened alloy system using discrete dislocation dynamics simulationsApr 15 2019We use three-dimensional discrete dislocation dynamics simulations (DDD) to study the evolution of interfacial dislocation network (IDN) in particle-strengthened alloy systems subjected to constant stress at high temperatures. We have modified the dislocation ... More
Electric Field Response In Breathing PyrochloresApr 15 2019We study the effects of a uniform electric field on the the ground state and excitations of the three-dimensional U(1) spin liquid phase of a breathing pyrochlore lattice, arising due to the coupling between the conventional (Maxwell) electric field and ... More
Mid-infrared (3-8 μm) $\text{Ge}_{1-y}\text{Sn}_y$ alloys (0.15 < $y$ < 0.30): synthesis, structural, and optical propertiesApr 15 2019$\text{Ge}_{1-y}\text{Sn}_y$ alloys with compositions in the 0.15 < $y$ < 0.30 range have been grown directly on Si substrates using a chemical vapor deposition approach that allows for growth temperatures as high as 290 $^{\circ}$C. The films show structural ... More
Out-of-equilibrium electrons lead to record thermionic emission in LaB6 with the Jahn-Teller instability of boron cageApr 15 2019Materials with low electron work function are of great demand in various branches of science and technology. LaB6 is among the most effective electron-beam sources with one of the highest brightness of thermionic emission. A deep understanding of the ... 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
Free log-likelihood as an unbiased metric for coherent diffraction imagingApr 15 2019Coherent Diffraction Imaging (CDI), a technique where an object is reconstructed from a single (2D or 3D) diffraction pattern, recovers the lost diffraction phases without a priori knowledge of the extent (support) of the object, which prevents an unambiguous ... More
Hidden mechanism for realizing flat bands: Embedding Lieb, kagome, and checkerboard lattices in other structuresApr 15 2019The interplay of hopping parameters that can give rise to flat bands in consequence of quantum interference in electronic, photonic, and other interesting materials has become an extensively studied topic. Most of the recognized structures having flat ... 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
Comparison of first-principles methods to extract magnetic parameters in ultra-thin films: Co/Pt(111)Apr 15 2019We compare three distinct computational approaches based on first-principles calculations within density functional theory to explore the magnetic exchange and the Dzyaloshinskii-Moriya interactions (DMI) of a Co monolayer on Pt(111), namely (i) the method ... More
Gd0.2Ce0.8O1.9/Y0.16Zr0.84O1.92 nanocomposite thin films for low temperature ionic conductivityApr 15 2019Gd0.2Ce0.8O1.9/Y0.16Zr0.84O1.92 (GDC/YSZ) nanocomposite is synthesized by a novel hybrid chemical route, where colloidal crystalline GDC nanoparticles from continuous hydrothermal synthesis are dispersed into a metalorganic YSZ matrix precursor. The result ... More
Towards thermoelectricity with density-functional based tight-binding: Accuracy of phonon bandstructuresApr 15 2019We calculate the phonon-dispersion relations of several two-dimensional materials and diamond using the density-functional based tight-binding approach (DFTB). Our goal is to verify if this numerically efficient method provides sufficiently accurate phonon ... 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
Crystal field coefficients for yttrium analogues of rare-earth/transition-metal magnets using density-functional theory in the projector-augmented wave formalismApr 15 2019We present a method of calculating crystal field coefficients of rare-earth/transition-metal (RE-TM) magnets within density-functional theory (DFT). The principal idea of the method is to calculate the crystal field potential of the yttrium analogue ("Y-analogue") ... More
Pattern Matching Analysis of Electron Backscatter Diffraction Patterns for Pattern Centre, Crystal Orientation and Absolute Elastic Strain Determination: Accuracy and Precision AssessmentApr 15 2019Pattern matching between target electron backscatter patterns (EBSPs) and dynamically simulated EBSPs was used to determine the pattern centre (PC) and crystal orientation, using a global optimisation algorithm. Systematic analysis of error and precision ... 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
Superconductivity in single-crystalline, aluminum- and gallium-hyperdoped germaniumApr 15 2019Superconductivity in group IV semiconductors is desired for hybrid devices combining both semiconducting and superconducting properties. Following boron doped diamond and Si, superconductivity has been observed in gallium doped Ge, however the obtained ... 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
Mode I and II Interlaminar Fracture in Laminated Composites: A Size Effect StudyApr 15 2019This work investigates the mode I and II interlaminar fracturing behavior of laminated composites and the related size effects. Fracture tests on geometrically scaled Double Cantilever Beam (DCB) and End Notch Flexure (ENF) specimens were conducted to ... 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
The mechanical response of cellular materials with spinodal topologiesApr 14 2019The mechanical response of cellular materials with spinodal topologies is numerically and experimentally investigated. Spinodal microstructures are generated by the numerical solution of the Cahn-Hilliard equation. Two different topologies are investigated: ... 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
Evolution of magnetic ordering in FeCr$_2$Se$_{4-x}$Te$_x$; $x$ = 0 -- 4.0Apr 14 2019We have systematically studied the magnetic properties of chromium chalcogene compounds FeCr$_2$Se$_{4-x}$Te$_x$. The FeCr2Se4 undergoes antiferromagnetic ordering below 222 K. Substitution of tellurium lowers the antiferromagnetic ordering temperature ... More
Superconducting Praseodymium SuperhydridesApr 14 2019Superhydrides have complex hydrogenic sublattices, and are important prototype systems to investigate metallization of hydrogen with potential room-temperature superconductivity. Here we synthesized praseodymium superhydrides (PrH9) via laser heating ... More
Tuning the metal-insulator transition in epitaxial SrVO3 films by uniaxial strainApr 14 2019Understanding of the metal-insulator transition (MIT) in correlated transition-metal oxides is a fascinating topic in condensed matter physics and a precise control of such transitions plays a key role in developing novel electronic devices. Here we report ... More
Giant Interfacial Thermal Resistance Arising From Materials With Mismatched Phonon StructuresApr 13 2019Previous researches only reported very small interfacial thermal resistances at room temperature due to limitations in sample combinations and methods. Taking cognizance of the importance of mismatched phonon structures, we report values up to $2*10^{-4}W^{-1}m^{2}K$, ... More
Valley-Layer Coupling: A New Design Principle for ValleytronicsApr 13 2019We introduce the concept of valley-layer coupling (VLC) in two-dimensional materials, where the low-energy electronic states in the emergent valleys have valley-contrasted layer polarization such that each state is spatially localized on the top or bottom ... More
Microwave programmable response of Co-based microwire polymer composites through wire microstructure and arrangement optimizationApr 13 2019Traditional approaches to realize microwave tunability in microwire polymer composites which mainly rely on topological factors, magnetic field/stress stimuli, and hybridization prove to be burdensome and restricted to rather narrow band frequencies. ... More