Latest in cond-mat.mtrl-sci

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Speeding-up Ab Initio Molecular Dynamics with Hybrid Functionals using Adaptively Compressed Exchange Operator based Multiple TimesteppingAug 22 2019Ab initio molecular dynamics (AIMD) simulations using hybrid density functionals and plane waves are of great interest owing to the accuracy of this approach in treating condensed matter systems. On the other hand, such AIMD calculations are not routinely ... More
Quantum Spin Liquid in a depleted triangular lattice Iridate K$_x$Ir$_y$O$_2$Aug 22 2019We report discovery of a new iridate family K$_x$Ir$_y$O$_2$ with depleted triangular lattice planes made up of edge sharing IrO$_6$ octahedra separated by K planes. Such a material interpolates between the triangular and honeycomb lattices and is a new ... More
Phase diagram and quantum criticality of Heisenberg spin chains with Ising-like interchain couplings -- Implication to YbAlO$_3$Aug 22 2019Motivated by recent progress on field-induced phase transitions in quasi-one-dimensional quantum antiferromagnets, we study the phase diagram of $S=1/2$ antiferromagnetic Heisenberg chains with Ising anisotropic interchain couplings under a longitudinal ... More
Thermally activated magnetization reversal in a FeCoB nanomagnet. High-precision measurement method of coercive field, delta, retention time and size of nucleation domainAug 22 2019Features of thermally-activated magnetization switching have been studied in a FeCoB nanomagnet using the N\'eel model. A method of a high-precision measurement of the coercive field, retention time, parameter delta and the size of the switching nucleation ... More
Royal Society Inaugural Article Perspective: Multiferroics Beyond Electric-Field Control of MagnetismAug 22 2019Multiferroic materials, with their combined and coupled magnetism and ferroelectricity, providea playground for studying new physics and chemistry as well as a platform for development ofnovel devices and technologies. Based on my July 2017 Royal Society ... More
Abundance of $\mathbb{Z}_2$ topological order in exfoliable two-dimensional insulatorsAug 22 2019Quantum spin Hall insulators are a class of two-dimensional materials with a finite electronic band gap in the bulk and gapless helical edge states. In the presence of time-reversal symmetry, $\mathbb{Z}_2$ topological order distinguishes the topological ... More
Perfect and controllable nesting in the small angle twist bilayer grapheneAug 22 2019Parallel ("nested") regions of a Fermi surface (FS) drive instabilities of the electron fluid, for example the spin density wave in elemental chromium. In one-dimensional materials, the FS is trivially fully nested (a single nesting vector connects two ... More
A parametric finite element method for solid-state dewetting problems in three dimensionsAug 22 2019We propose a parametric finite element method (PFEM) for efficiently solving the morphological evolution of solid-state dewetting of thin films on a flat rigid substrate in three dimensions (3D). The interface evolution of the dewetting problem in 3D ... More
High-Pressure Synthesis of Magnetic Neodymium PolyhydridesAug 22 2019Search for room-temperature superconductivity is inspired by the unique properties of the electron-phonon interaction in metal superhydrides.Encouraged by the recently found highest-$T_C$ superconductor $fcc$-$LaH_{10}$, here we discover several polyhydrides ... More
High-throughput fabrication and semi-automated characterization of oxide thin film transistorsAug 22 2019High throughput experimental methods are known to accelerate the rate of research, development, and deployment of electronic materials. For example, thin films with lateral gradients in composition, thickness, or other parameters have been used alongside ... More
Strain heterogeneity and micro-damage nucleation under tensile stresses in an Mg-5Al-3Ca alloy with an intermetallic skeletonAug 22 2019Strain heterogeneity at the microstructural level plays a vital role in the deformation and fracture behaviour of dual or multi-phase materials. In the present work, the strain heterogeneity, localization and partitioning arising at the sub-micron scale ... More
VASPKIT: A Pre- and Post-Processing Program for VASP codeAug 22 2019The VASPKIT program aims to manipulate and analyze the input and output files from the widely-used VASP electronic structure package. It mainly includes two modules. The pre-processing module is designed to prepare and manipulate input files such as generation ... More
Influence of structure and cation distribution on magnetic anisotropy and damping in Zn/Al doped nickel ferritesAug 22 2019An in-depth analysis of Zn/Al doped nickel ferrite with a nominal composition of Ni$_\text{0.65}$Zn$_\text{0.35}$Al$_\text{0.8}$Fe$_\text{1.2}$O$_\text{4}$ was conducted to gain insight into the magnetic properties interesting for applications in spintronics. ... More
Non-localized states and high hole mobility in amorphous germaniumAug 22 2019Covalent amorphous semiconductors, such as amorphous silicon (a-Si) and germanium (a-Ge), are commonly believed to have localized electronic states at the top of the valence band and the bottom of the conduction band. Electrical conductivity is thought ... More
Synthesis of strain-relaxed Ge-Sn alloys using ion implantation and pulsed laser meltingAug 22 2019Ge-Sn alloys with a sufficiently high concentration of Sn is a direct bandgap group IV material. Recently, ion implantation followed by pulsed laser melting has been shown to be a promising method to realize this material due to its high reproducibility ... More
Molecular characterization of macroscopic aerogels of single-walled carbon nanotubesAug 22 2019Single-walled carbon nanotubes (SWCNT) can be assembled into various macroscopic architectures, most notably continuous fibers and films, produced currently on a kilometer per day scale by floating catalyst chemical vapor depositionand spinning from an ... More
Mottness versus unit-cell doubling as the driver of the insulating state in 1T-TaS2Aug 22 2019If a material with an odd number of electrons per unit cell turns out to be insulating, Mott localisation may be invoked as an explanation. This is widely accepted for the layered compound 1T-TaS2, which has a low-temperature insulating phase comprising ... More
Controllable thickness inhomogeneity and Berry-curvature-engineering of anomalous Hall effect in SrRuO3 ultrathin filmsAug 22 2019In quantum matters hosting electron-electron correlation and spin-orbit coupling, spatial inhomogeneities, arising from competing ground states, can be essential for determining and understanding topological properties. A prominent example is Hall anomalies ... More
Size dependent yield hardness induced by surface energyAug 22 2019Size dependent hardness has long been reported in nanosized indentations, however the corresponding explanation is still in exploration. In this paper, we examine the influence of surface energy on the hardness of materials under spherical indentation. ... More
Anomalous Hall effect at the spontaneously electron-doped polar surface of PdCoO2 ultrathin filmsAug 22 2019We revealed the electrical transport through surface ferromagnetic states of a nonmagnetic metal PdCoO2. Electronic reconstruction at the Pd-terminated surface of PdCoO2 induces Stoner-like ferromagnetic states, which could lead to spin-related phenomena ... More
Signatures of coupling between spin waves and Dirac fermions in YbMnBi$_2$Aug 21 2019We present inelastic neutron scattering (INS) measurements of magnetic excitations in YbMnBi$_2$, which reveal features consistent with a direct coupling of magnetic excitations to Dirac fermions. In contrast with the large broadening of magnetic spectra ... More
Dynamic disorder induced memristance in amorphous solidsAug 21 2019Motivated by the recent discovery of several amorphous oxides exhibiting remarkable threshold switching and hysteresis in the current-voltage response, we outline a purely quantum mechanism of memristance based on Anderson localization. Concerting first ... More
Small polarons and the Janus nature of $\text{TiO}_\text{2}(110)$Aug 21 2019Polarons are ubiquitous in many semiconductors and have been linked with conductivity and optical response of materials for photovoltaics and heterogeneous catalysis, yet how surface polarons influence adsorption remains unclear. Here, by modelling the ... More
Nonaffine lattice dynamics with the Ewald method reveals strongly nonaffine elasticity of α-quartzAug 21 2019A lattice dynamical formalism based on nonaffine response theory is derived for non-centrosymmetric crystals, accounting for long-range interatomic interactions using the Ewald method. The framework takes equilibrated static configurations as input to ... More
Inverse Structural Design of Graphene/Boron Nitride Hybrids by Regressional GANAug 21 2019Inverse design of materials with desired properties is currently laborious and heavily relies on intuition of researchers through a trial-and-error process. The massive combinational spaces due to the constituent elements and their structural configurations ... More
Fatigue-resistant high-performance elastocaloric materials via additive manufacturingAug 21 2019Elastocaloric cooling, which exploits the latent heat released and absorbed as stress-induced phase transformations are reversibly cycled in shape memory alloys, has recently emerged as a frontrunner in non-vapor-compression cooling technologies. The ... More
Apollonian Packing in Polydisperse EmulsionsAug 21 2019We have discovered the existence of polydisperse High Internal-Phase-Ratio Emulsions (HIPE) in which the internal-phase droplets, present at 95% volume fraction, remain spherical and organize themselves in the available space according to Apollonian packing ... More
Microstructure and Elastic Constants of Transition Metal Dichalcogenide Monolayers from Friction and Shear Force MicroscopyAug 21 2019Optical and electrical properties of two-dimensional transition metal dichalcogenides (TMDCs) grown by chemical vapor deposition (CVD) are strongly determined by their microstructure. Consequently, the visualization of spatial structural variations is ... More
Impact of a doping-induced space-charge region on the collection of photo-generated charge carriers in thin-film solar cells based on low-mobility semiconductorsAug 21 2019Unintentional doping of the active layer is a source for lowered device performance in organic solar cells. The effect of doping is to induce a space-charge region within the active layer, generally resulting in increased recombination losses. In this ... More
Half-metallic ferromagnetism and Ru-induced localization in quaternary Heusler alloy CoRuMnSiAug 21 2019We report a combined theoretical and experimental investigation of half-metallic ferromagnetism in equiatomic quaternary Heusler alloy CoRuMnSi. Room temperature XRD analysis reveals that the alloy crystallizes in L21 disorder instead of pristine Y-type ... More
Pure spin current in a robust pigment-red filmAug 21 2019We report the spin current properties in a pigment-red (perylene-3,4,9,10-tetracarboxylic dianhydride: PTCDA) film prepared by thermal evaporation. In a palladium(Pd)/PTCDA/Ni80Fe20 tri-layer sample, a pure spin-current is generated in the PTCDA layer ... More
Ordering phenomena of spin trimers accompanied by large geometrical Hall effectAug 21 2019The wavefuntion of conduction electrons moving in the background of a non-coplanar spin structure can gain a quantal phase - Berry phase - as if the electrons were moving in a strong fictitious magnetic field. Such an emergent magnetic field effect is ... More
Two-dimensional Ferromagnetic van der Waals CrX3 (X=Cl, Br, I) Monolayers with Enhanced Anisotropy and Curie TemperatureAug 21 2019Among the recently widely studied van der Waals layered magnets CrX3 (X=Cl, Br, I), CrCl3 monolayer (ML) is particularly puzzling as it is solely shown by experiments to have an in-plane magnetic easy axis and, furthermore, all of previous first-principles ... More
Designing Anisotropic Microstructures with Spectral Density FunctionAug 21 2019Materials' microstructure strongly influences its performance and is thus a critical aspect in design of functional materials. Previous efforts on microstructure mediated design mostly assume isotropy, which is not ideal when material performance is dependent ... More
A linear-scaling algorithm for rapid computation of inelastic transitions in the presence of multiple electron scatteringAug 20 2019Strong multiple scattering of the probe in scanning transmission electron microscopy (STEM) means image simulations are usually required for quantitative interpretation and analysis of elemental maps produced by electron energy-loss spectroscopy (EELS). ... More
Magic high-order harmonics from a quasi-one-dimensional hexagonal solidAug 20 2019High-order harmonic generation (HHG) from atoms is a coherent light source that opens up attosecond physics, but it is the application of HHG to solids that brings much of excitement for the last decade. Here we report a completely new kind of harmonics ... More
Ta, Ti and Hf effects on Nb$_3$Sn high-field performance: temperature-dependent dopant occupancy and failure of Kramer extrapolationAug 20 2019The increasing demand for improving the high-field (16-22 T) performance of Nb$_3$Sn conductors requires a better understanding of the properties of modern wires much closer to irreversibility field, H$_{Irr}$. In this study we investigated the impact ... More
Topological elasticity of flexible structuresAug 20 2019Flexible mechanical metamaterials possess repeating structural motifs that imbue them with novel, exciting properties including programmability, anomalous elastic moduli and nonlinear and robust response. We address such structures via micromorphic continuum ... More
Li4Ti5O12: A Visible-to-Infrared Broadband Electrochromic Material for Optical and Thermal ManagementAug 20 2019Broadband electrochromism from visible to infrared wavelengths is attractive for applications like smart windows, thermal-camouflage, and temperature control. In this work, the broadband electrochromic properties of Li4Ti5O12 (LTO) and its suitability ... More
Factors limiting ferroelectric field-effect doping in complex-oxide heterostructuresAug 20 2019Ferroelectric field-effect doping has emerged as a powerful approach to manipulate the ground state of correlated oxides, opening the door to a new class of field-effect devices. However, this potential is not fully exploited so far, since the size of ... More
Two-dimensional covalent crystals by chemical conversion of thin van der Waals materialsAug 20 2019Most of the studied two-dimensional (2D) materials have been obtained by exfoliation of van der Waals crystals. Recently, there has been growing interest in fabricating synthetic 2D crystals which have no layered bulk analogues. These efforts have been ... More
Machine-learning interatomic potential for radiation damage and defects in tungstenAug 20 2019We introduce a machine-learning interatomic potential for tungsten using the Gaussian Approximation Potential framework. We specifically focus on properties relevant for simulations of radiation-induced collision cascades and the damage they produce, ... More
Structure of amorphous Cu$_2$GeTe$_3$ and a model for its fast phase-change mechanismAug 20 2019The structure of amorphous Cu$_2$GeTe$_3$ is investigated by a combination of anomalous x-ray scattering and extended x-ray absorption fine structure experiments. The experimental data are analyzed with a reverse Monte Carlo modeling procedure, and interpreted ... More
Energy-level alignment at organic/inorganic interfaces from first principles: Example of poly(\emph{para}-phenylene) / rock-salt ZnO(100)Aug 20 2019By means of full-potential all-electron density-functional theory and many-body perturbation theory, we compute the band alignment at a prototypical hybrid inorganic/organic interface. The electronic properties of a model system built of poly(\emph{para}-phenylene) ... More
Phonons and Anomalous Lattice Behaviour in KMnAg3(CN)6 and KNiAu3(CN)6: Inelastic Neutron Scattering and First-Principles CalculationsAug 20 2019Cyanide based framework compounds are known to show large negative thermal expansion behaviour. Here we report the phonon and anomalous lattice behavior of two metal cyanide framework compounds i.e. KMnAg3(CN)6 and KNiAu3(CN)6. We have studied the role ... More
Surface nucleation of the paraelectric phase in ferroelectric BaTiO3: Atomic scale mappingAug 20 2019In ferroelectricity, atomic-scale dipole moments interact collectively to produce strong electro-mechanical coupling and switchable macroscopic polarization. Hence, the functionality of ferroelectrics emerges at a solid-solid phase transformation that ... More
Design of a High Strength, High Ductility 12 wt% Mn Medium Manganese Steel With Hierarchical Deformation BehaviourAug 20 2019A novel medium Mn steel of composition Fe-12Mn-4.8Al-2Si-0.32C-0.3V was manufactured with 1.09 GPa yield strength, 1.26 GPa tensile strength and 54% elongation. The thermomechanical process route was designed to be industrially translatable and consists ... More
Detection of hole pockets in type-II Weyl semimetal MoTe$_2$ from Shubnikov-de Haas quantum oscillationsAug 20 2019The bulk electronic structure of $T_d$-MoTe$_2$ features large hole Fermi pockets at the Brillouin zone center ($\Gamma$) and two electron Fermi surfaces along the $\Gamma-X$ direction. However, the large hole pockets, whose existence has important implications ... More
Materials Structure, Properties and Dynamics through Scanning Transmission Electron MicroscopyAug 20 2019Scanning transmission electron microscopy (STEM) has advanced rapidly in the last decade thanks to the ability to correct the major aberrations of the probe forming lens. Now atomic-sized beams are routine, even at accelerating voltages as low as 40 kV, ... More
Unconventional crystal field splitting in non-centrosymmetric BaTiO$_3$ thin filmsAug 20 2019Understanding the crystal field splitting and orbital polarization in non-centrosymmetric systems such as ferroelectric materials is fundamentally important. In this study, taking BaTiO$_3$ (BTO) as a representative material we investigate titanium crystal ... More
Efficient Terahertz Harmonic Generation with Coherent Acceleration of Electrons in the Dirac Semimetal Cd3As2Aug 20 2019High harmonic generation (HHG), the frequency conversion of an ac electric field, plays a key role in high-speed electronics at terahertz (THz) frequencies as well as in ultrafast photonics. Recent discoveries of material-based HHG have facilitated the ... More
Quantum anomalous Hall effect driven by magnetic proximity coupling in all-telluride based heterostructureAug 20 2019The quantum anomalous Hall effect (QAHE) is an exotic quantum phenomenon originating from dissipation-less chiral channels at the sample edge. While the QAHE has been observed in magnetically doped topological insulators (TIs), exploiting magnetic proximity ... More
Measurements of Nonequilibrium Interatomic Forces in Photoexcited BismuthAug 20 2019We determine experimentally the excited-state interatomic forces in photoexcited bismuth. The forces are obtained by a constrained least-squares fit of the excited-state dispersion obtained by femtosecond time-resolved x-ray diffuse scattering to a fifteen-nearest ... More
Coexistence of spin frustration and spin unfrustration induced spontaneous exchange bias in Heusler alloysAug 20 2019The mechanism of spontaneous exchange bias (SEB) and the dominant factor of its blocking temperature are still unclear in Heusler alloys. Here, the related investigations are performed in Mn2Ni1.5Al0.5 Heusler alloys with SEB. The results of both magnetic ... More
Three-dimensional graphene networks modified with acetylenic linkages for high-performance optoelectronics and Li-ion battery anode materialAug 20 2019Searching for three-dimensional(3D) semiconducting carbon allotropes with proper bandgaps and excellent optoelectronic properties is always the chasing goal for the new emerging all-carbon optoelectronics. On the other side, 3D carbon materials have also ... More
Coherent Epitaxial Semiconductor-Ferromagnetic Insulator InAs/EuS Interfaces: Band Alignment and Magnetic StructureAug 19 2019Hybrid semiconductor-ferromagnetic insulator heterostructures are interesting due to their tunable electronic transport, self-sustained stray field and local proximitized magnetic exchange. In this work, we present lattice matched hybrid epitaxy of semiconductor ... More
Electrodynamics of tilted Dirac/Weyl materials: A unique platform for unusual surface plasmon polaritonsAug 19 2019The electrodynamics of Weyl semimetals (WSMs) is an extension of Maxwell's theory where in addition to field strength tensor $F_{\mu\nu}$, an axion field enters the theory which is parameterized by a four-vector $b^\mu=(b_0,\bf b)$. In the tilted Weyl ... More
Nanostructure engineering of epitaxial piezoelectric α-quartz thin films on siliconAug 19 2019The monolithic integration of sub-micron quartz structures on silicon substrates is a key issue for the future development of telecommunication to the GHz frequencies. Here we report unprecedented large-scale fabrication of ordered arrays of piezoelectric ... More
Giant thermal magnetoconductivity in CrCl$_3$ and a general model for spin-phonon scatteringAug 19 2019Insulating quantum magnets lie at the forefront both of fundamental research into quantum matter and of technological exploitation in the increasingly applied field of spintronics. In this context, the magnetic thermal transport is a particularly sensitive ... More
Amorphous Ferrimagnets: an Ideal Host for Ultra-Small Skyrmions at Room TemperatureAug 19 2019Recently, magnetic skyrmion has emerged as an active topic of fundamental study and applications in magnetic materials research. Magnetic skyrmions are vortex-like spin excitations with topological protection and therefore are more robust to pinning compared ... More
Semi-Local Parameterization of the Electron Localization Function in Second-Order Density GradientsAug 19 2019The electron localization function (ELF) is a universal measure of electron localization that allows for, e.g., an effective characterization of physical bonds in molecular and solid state systems. In the context of the widely used Kohn-Sham density-functional ... More
Highly Sensitive, Fast Graphene Photodetector with Responsivity $>10^6$ A/W Using Floating Quantum Well GateAug 19 2019Graphene, owing to its zero bandgap electronic structure, is promising as an absorption material for ultra-wideband photodetection applications. However, graphene-absorption based detectors inherently suffer from poor responsivity due to weak absorption ... More
Low temperature growth and optical properties of α-Ga2O3 deposited on sapphire by plasma enhanced atomic layer depositionAug 19 2019Plasma enhanced atomic layer deposition was used to deposit thin films of Ga2O3 on to c-plane sapphire substrates using triethylgallium and O2 plasma. The influence of substrate temperature and plasma processing parameters on the resultant crystallinity ... More
Light emission from the layered metal 2H-TaSe$_2$ and its potential applicationsAug 19 2019Conventional metals, in general, do not exhibit strong photoluminescence. 2H-TaSe$_2$ is a layered transition metal dichalcogenide that possesses metallic property with charge density wave characteristics. Here we show that 2H-TaSe$_2$ exhibits a surprisingly ... More
Interconversion of multiferroic domains and domain wallsAug 19 2019Materials with long-range order like ferromagnetism or ferroelectricity exhibit uniform, yet differently oriented three-dimensional regions called domains that are separated by two-dimensional topological defects termed domain walls\cite{Tagantsev2010,AlexHubert1998}. ... More
Influence of irradiation on defect spin coherence in silicon carbideAug 19 2019Irradiation-induced lattice defects in silicon carbide (SiC) have already exceeded their previous reputation as purely performance-inhibiting. With their remarkable quantum properties, such as long room-temperature spin coherence and the possibility of ... More
Symbolic Regression Discovery of New Perovskite Catalysts with High Oxygen Evolution Reaction ActivityAug 19 2019Symbolic regression (SR) is an emerging method for building analytical formulas to find models that best fit data sets. Here, SR was used to guide the design of new oxide perovskite catalysts with improved oxygen evolution reaction (OER) activities. An ... More
Magnetic Proximity Effect in a van der Waals Moiré SuperlatticeAug 19 2019We investigate the magnetic proximity effect in van der Waals heterostructure formed by a monolayer semiconductor stacked on a 2D ferromagnet, where the lattice mismatch and twisting between the layers typically lead to the formation of moir\'e pattern. ... More
Tunable Giant Rashba-type Spin Splitting in PtSe$_2$/MoSe$_2$ HeterostructureAug 19 2019Finding materials with tunable and strong Rashba spin-orbit coupling is the central theme for realizing the Datta-Das spin field-effect transistor. In this work, we report a giant Rashba-type spin splitting in two-dimensional heterostructure PtSe$_2$/MoSe$_2$ ... More
Multifunctional Composites for Elastic and Electromagnetic Wave PropagationAug 19 2019Composites are ideally suited to achieve desirable multifunctional effective properties, since the best properties of different materials can be judiciously combined with designed microstructures. Here we establish the first cross-property relations for ... More
Threading-Induced Dynamical Transition in Chimeric PolymersAug 19 2019The relationship between polymer topology and bulk rheology remains a key question in soft matter physics. Architecture-specific constraints (or threadings) are thought to control the dynamics of circular polymers in ring-linear blends where the dynamics ... More
Electron-phonon coupling and hot electron thermalization in titanium nitrideAug 19 2019We have studied the thermalization of hot carriers in both pristine and defective titanium nitride (TiN) using a two-temperature model. All parameters of this model, including the electron-phonon coupling parameter, were obtained from first-principles ... More
Breakdown of Raman Selection Rules By Fröhlich Interaction in Few-Layer WS$_2$Aug 19 2019The Raman selection rules arise from the crystal symmetry and then determine the Raman activity and polarization of scattered phonon modes. However, these selection rules can be broken in resonant process due to the strong electron-phonon coupling effect. ... More
Exploring the role of electronic structure on photo-catalytic behavior of carbon-nitride (C$_{3}$N$_{4}$) polymorphsAug 19 2019We provide a comprehensive account of structural, electronic, and optical properties of carbon-nitride (C$_{3}$N$_{4}$) polymorphs. We employ density-functional theory with two different basis sets for better predictions of structural and electronic band-gap ... More
Scanning tunneling microscope characterizations of a circular graphene resonator realized with p-p junctionsAug 19 2019Using low-temperature high-magnetic-field scanning tunneling microscopy and spectroscopy (STM/STS), we systematically study a graphene quantum dot (GQD) defined by a circular graphene p-p junction. Inside the GQD, we observe a series of quasi-bound states ... More
Ultraviolet to Near-infrared Single Photon Emitters in hBNAug 19 2019In the field of quantum photon sources, single photon emitter from solid is of fundamental importance for quantum computing, quantum communication, and quantum metrology. However, it has been an ultimate but seemingly distant goal to find the single photon ... More
Ultraviolet to Near-infrared Single Photon Emitters in hBNAug 19 2019Aug 20 2019In the field of quantum photon sources, single photon emitter from solid is of fundamental importance for quantum computing, quantum communication, and quantum metrology. However, it has been an ultimate but seemingly distant goal to find the single photon ... More
Ultraviolet to Near-infrared Single Photon Emitters in hBNAug 19 2019Aug 21 2019In the field of quantum photon sources, single photon emitter from solid is of fundamental importance for quantum computing, quantum communication, and quantum metrology. However, it has been an ultimate but seemingly distant goal to find the single photon ... More
Reverse chemistry of iron in the deep EarthAug 19 2019In this work, we demonstrate a remarkable change of chemical trend of Iron under high pressure that is of great importance for understanding the distribution of elements in the Earth's mantle and core. Using first principles crystal structure search method, ... More
Influence of chemical stability on the fabrication of MnGa-based devicesAug 18 2019Ferromagnetic films of L10-ordered MnGa have shown promise not only in the applications in ultrahigh-density magnetic recording and spintronic memories, oscillators, and sensors, but also in controllable studies of novel electrical transport phenomena. ... More
Maximizing the spin-orbit torque efficiency of Pt/Ti multilayers by optimization of the tradeoff between the intrinsic spin Hall conductivity and carrier lifetimeAug 18 2019We report a comprehensive study of the maximization of the spin Hall ratio ({\theta}SH) in Pt thin films by the insertion of sub-monolayer layers of Ti to decrease carrier lifetime while minimizing the concurrent reduction in the spin Hall conductivity. ... More
Accelerated relaxation in disordered solids under cyclic loading with alternating shear orientationAug 18 2019The effect of alternating shear orientation during cyclic loading on the relaxation dynamics in disordered solids is examined using molecular dynamics simulations. The model glass was initially prepared by rapid cooling from the liquid state and then ... More
Determination of fracture toughness of thin-film amorphous silicon using spiral crack structuresAug 18 2019We prepared thin layers of amorphous silicon by deposition of a liquid-phase polysilane precurser on glass substrate. Raman scattering provides evidence for residual tensile stress in the silicon, which is evaluated quantitatively. Under treatment with ... More
Meyer-Neldel and anti-Meyer-Neldel rule in microcrystalline silicon and silicon carbide examined with Hall measurementsAug 18 2019We study the electronic transport in lightly phosphorus-doped hydrogenated microcrystalline silicon ($\mu$c-Si:H) and nominally undoped hydrogenated silicon carbide ($\mu$c-SiC:H) by temperature-dependent Hall measurements. The material properties cover ... More
Influence of hydrogen radicals treatment on layers and solar cells made of solution-processed amorphous siliconAug 18 2019Solution-processed amorphous silicon is a promising material for semiconductor devices. Unfortunately, its manufacturing leaves a high density of defects in the layer, which can be reduced by a treatment with hydrogen radicals. Here, we present an optimized ... More
Pressure induced electronic structure transformation of topological semimetalAug 18 2019We study the electronic structure change of yttrium trihydride $\mathrm{YH_3}$ by applying a hydrostatic pressure. At zero pressure, $\mathrm{YH_3}$ has the structure with energy favored symmetry group $P\bar{3}c1$ (165). From first principle calculation, ... More
Magnetic Entropy in a Non-Collinear Weak Ferromagnetic YCrO3Aug 18 2019We carried out temperature and field dependent magnetic measurements to understand the evolution of magnetic non-collinearity near antiferromagnetic phase in conjunction with the evolution of magnetic entropy near phase transition. We observed the maximum ... More
Anomalous magnetic behavior and complex magnetic structure of proximate LaCrO3 LaFeO3 systemAug 18 2019We investigated complex magnetic properties of multifunctional LaCrO3-LaFeO3 system. The magnetic measurements substantiate the presence of competing complex magnetic ordering against temperature, showing paramagnetic to ferrimagnetic transition at 300 ... More
Electron \textit{g}-factor engineering for non-reciprocal spin photonicsAug 18 2019We study the interplay of electron and photon spin in non-reciprocal materials. Traditionally, the primary mechanism to design non-reciprocal photonic devices has been magnetic fields in conjunction with magnetic oxides, such as iron garnets. In this ... More
Universal features in "stickiness" criteria for soft adhesion with rough surfacesAug 18 2019A very interesting recent paper by Dalvi et al. has demonstrated convincingly with adhesion experiments of a soft material with a hard rough material that the simple energy idea of Persson and Tosatti works reasonably well, namely the reduction in apparent ... More
Confinement effect on solar thermal heating process of TiN solutionsAug 18 2019We propose a theoretical approach to describe quantitatively the heating process in aqueous solutions of dispersed TiN nanoparticles under solar illumination. The temperature gradients of solution with different concentrations of TiN nanoparticles are ... More
Electronic phase separation at LaAlO3/SrTiO3 interfaces tunable by oxygen deficiencyAug 17 2019Electronic phase separation is crucial for the fascinating macroscopic properties of the LaAlO3/SrTiO3 (LAO/STO) paradigm oxide interface, including the coexistence of superconductivity and ferromagnetism. We investigate this phenomenon using angle-resolved ... More
Stacking transition in rhombohedral graphiteAug 17 2019Few layer graphene (FLG) has been recently intensively investigated for its variable electronic properties defined by a local atomic arrangement. While the most natural layers arrangement in FLG is ABA (Bernal) stacking, a metastable ABC (rhombohedral) ... More
Modeling spontaneous charge transfer at metal/organic hybrid heterostructuresAug 17 2019Hybrid materials are crucial in photovoltaics where the overall efficiency of the heterostructure is closely related to the level of charge transfer at the interface. Here, using various metal / poly(3-hexylthiophene)(P3HT) heterostructure models, we ... More
Carbon-related Bilayers: Nanoscale Building Blocks for Self-Assembly NanomanufacturingAug 17 2019Using a first-principles total energy methodology, we investigated the properties of graphene-like carbon mono and bilayers, functionalized with nitrogen and boron atoms. The resulting stable structures were explored in terms of their potential use as ... More
Low-Frequency Noise in Low-Dimensional van der Waals MaterialsAug 16 2019The emergence of graphene and two-dimensional van der Walls materials renewed interest to investigation of the low-frequency noise in the low-dimensional systems. The layered van der Waals materials offers unique opportunities for studying the low-frequency ... More
Itinerant ferromagnetism and intrinsic anomalous Hall effect in amorphous iron-germaniumAug 16 2019The amorphous iron-germanium system ($a$-Fe$_x$Ge$_{1-x}$) lacks long-range structural order and hence lacks a meaningful Brillouin zone. The magnetization of $a$-Fe$_x$Ge$_{1-x}$ is well explained by the Stoner model for Fe concentrations $x$ above the ... More
A case study of bilayered spin-$1/2$ square lattice compound [VO(HCOO)$_2\cdot$(H$_2$O)]Aug 16 2019We present the synthesis and a detail investigation of structural and magnetic properties of polycrystalline [VO(HCOO)$_2\cdot$(H$_2$O)] by means of x-ray diffraction, magnetic susceptibility, high-field magnetization, heat capacity, and electron spin ... More
Scaling Analysis of Anomalous Hall Resistivity in the Co$_{2}$TiAl Heusler AlloyAug 16 2019A comprehensive magnetotransport study including resistivity ($\rho_{xx}$) at various fields, isothermal magnetoresistance and Hall resistivity ($\rho_{xy}$) has been carried out at different temperatures on the Co$_{2}$TiAl Heusler alloy. Co$_{2}$TiAl ... More
Non-Trivial Topological Phase in the Sn_{1-x}In_xTe SuperconductorAug 16 2019Whereas SnTe is a inverted band gap topological crystalline insulator, the topological phase of the alloy Sn_{1-x}In_xTe, a topological superconductor candidate, has not been clearly studied so far. Our calculations show that the Sn_{1-x}In_xTe band gap ... More