Latest in cond-mat.mtrl-sci

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Solid Lubrication with MoS$_2$: A ReviewJun 13 2019Molybdenum disulfide (MoS$_2$) is one of the most broadly utilized solid lubricants with a wide range of applications, including but not limited to those in the aerospace/space industry. Here we present a focused review of solid lubrication with MoS$_2$ ... More
Comment on "Nonreciprocal cavities and the time-bandwidth limit"Jun 13 2019In their paper in Optica 6, 104 (2019), Mann et al. claim that time-invariant nonreciprocal cavities cannot overcome the time-bandwidth limit, based on their numerical analysis and temporal coupled-mode theory of an example structure. In this comment, ... More
Dirac Fermions in Antiferromagnetic FeSn Kagome Lattices with Combined Space Inversion and Time Reversal SymmetryJun 13 2019Symmetry principles play a critical role in formulating the fundamental laws of nature$^{1}$, with a large number of symmetry-protected topological states identified in recent studies of quantum materials$^{2,3}$. As compelling examples, massless Dirac ... More
Comment on arXiv:1807.08572, "Coexistence of Diamagnetism and Vanishingly Small Electrical Resistance at Ambient Temperature and Pressure in Nanostructures"Jun 13 2019A recent preprint arXiv:1807.08572 reported the observation of a transition in Ag/Au nanoparticle composites near room temperature and at ambient pressure, to a vanishingly small four-probe resistance, which was tentatively identified as a percolating ... More
Device Chemistry of Graphene TransistorsJun 13 2019Graphene is an attractive material for microelectronics applications, given such favourable electrical characteristics as high mobility, high operating frequency, and good stability. If graphene is to be implemented in electronic devices on a mass scale, ... More
Bounds on the energy of a soft cubic ferromagnet with large magnetostrictionJun 13 2019We complete the analysis initiated in [5] on the micromagnetics of cubic ferromagnets in which the role of magnetostriction is significant. We prove ansatz-free lower bounds for the scaling of the total micromagnetic energy including magnetostriction ... More
Can we determine the carrier diffusion length in GaN from cathodoluminescence maps around threading dislocations?Jun 13 2019We investigate, both theoretically and experimentally, the drift, diffusion, and recombination of excitons in the strain field of an edge threading dislocation intersecting the GaN{0001} surface. We calculate and measure hyperspectral cathodoluminescence ... More
Setup for simultaneous electrochemical and color impedance measurements of electrochromic films: theory, assessment, and test measurementJun 13 2019Combined frequency-resolved techniques are suitable to study electrochromic (EC) materials. We present an experimental setup for simultaneous electrochemical and color impedance studies of EC systems in transmission mode and estimate its frequency-dependent ... More
Ion beam sputtering of silicon: Energy distributions of sputtered and scattered ionsJun 13 2019The properties of sputtered and scattered ions are studied for ion beam sputtering of Si by bombardment with noble gas ions. The energy distributions in dependence on ion beam parameters (ion energy: 0.5 - 1 keV; ion species: Ne, Ar, Xe) and geometrical ... More
Passivation-induced physicochemical alterations of the native surface oxide film on 316L austenitic stainless steelJun 13 2019Time of Flight Secondary Ion Mass Spectroscopy, X-Ray Photoelectron Spectroscopy, in situ Photo-Current Spectroscopy and electrochemical analysis were combined to characterize the physicochemical alterations induced by electrochemical passivation of the ... More
Magnetoelasticity of $\mathrm{Co_{25}}\mathrm{Fe_{75}}$ thin filmsJun 13 2019We investigate the magnetoelastic properties of $\mathrm{Co_{25}}\mathrm{Fe_{75}}$ and $\mathrm{Co_{10}}\mathrm{Fe_{90}}$ thin films by measuring the mechanical properties of a doubly clamped string resonator covered with multi-layer stacks containing ... More
Giant magnetic field from moiré induced Berry phase in homobilayer semiconductorsJun 13 2019When quasiparticles move in condensed matters, the texture of their internal quantum structure as a function of position and momentum can give rise to Berry phases that have profound effects on materials properties. Seminal examples include the anomalous ... More
Full spatiotemporal control of laser-excited periodic surface deformationsJun 13 2019We demonstrate full control of acoustic and thermal periodic deformations at solid surfaces down to sub-nanosecond time scales and few-micrometer length scales via independent variation of the temporal and spatial phase of two optical transient grating ... More
Type-II Weyl Fermions in SuperconductorsJun 13 2019Based on the first-principles calculations and consistent experimental measurements, we propose that the hexagonal phase of ternary transition metal pnictides TT'X (T=Zr, Hf; T'=Ru; X=P, As), which are well-known noncentrosymmetric superconductors with ... More
Wafer-Scale and Deterministic Patterned Growth of Monolayer MoS2 via Vapor-Liquid-Solid MethodJun 13 2019Vapor transportation is the core process in growing transition-metal dichalcogenides (TMDCs) by chemical vapor deposition (CVD). One inevitable problem is the spatial inhomogeneity of the vapors. The non-stoichiometric supply of transition-metal precursors ... More
Self-driving laboratory for accelerated discovery of thin-film materialsJun 12 2019Clean energy technologies are notoriously slow to commercialize because discovering and optimizing new materials for applications typically takes over a decade. Self-driving laboratories that iteratively design, execute, and learn from experiments in ... More
Ripplocation in graphite nanoplatelets during sonication assisted liquid phase exfoliationJun 12 2019Defects induced by liquid-phase exfoliation of graphite using sonication were studied. It was shown that localized impact by cavitation shock waves can produce bulk ripplocations and various types of dislocations in graphite nanoplatelets. Formation of ... More
Unraveling the role of dipolar vs. Dzyaloshinskii-Moriya interaction in stabilizing compact magnetic skyrmionsJun 12 2019Magnetic skyrmions have been the subject of extensive experimental studies in ferromagnetic thin films and multilayers, revealing a diversity in their size, stability and internal structure. While the orthodox skyrmion theory focuses on the Dzyaloshinskii-Moryia ... More
Thermally induced band gap increase and high thermoelectric figure of merit of n-type PbTeJun 12 2019Unlike in many other semiconductors, the band gap of PbTe increases considerably with temperature. We compute the thermoelectric transport properties of n-type PbTe from first principles including the temperature variation of the electronic band structure. ... More
Developing an improved Crystal Graph Convolutional Neural Network framework for accelerated materials discoveryJun 12 2019The recently proposed crystal graph convolutional neural network (CGCNN) offers a highly versatile and accurate machine learning (ML) framework by learning material properties directly from graph-like representations of crystal structures ("crystal graphs"). ... More
Entropic elasticity and negative thermal expansion in a simple cubic crystalJun 12 2019While most solids expand when heated, some materials show the opposite behavior: negative thermal expansion (NTE). In polymers and biomolecules, NTE originates from the entropic elasticity of an ideal, freely-jointed chain. The origin of NTE in solids ... More
Thermodynamic origin of solute-enriched stacking-fault in dilute Mg-Zn-Y alloysJun 12 2019We investigate thermodynamic behaviors of dilute Mg-Zn-Y ternary alloys to form a unique solute-enriched stacking-fault (SESF), which is an intrinsic-II type stacking-fault (I2-SF) enriched by the Zn and Y atoms and represents the structural-unit of the ... More
Elastic propagation of fast electron vortices through amorphous materialsJun 12 2019In this work, we study the elastic scattering behavior of electron vortices when propagating through amorphous samples. We use a formulation of the multislice approach in cylindrical coordinates to theoretically investigate the redistribution of intensity ... More
Transient Analysis during Maximum Power Point Tracking (TrAMPPT) to Assess Dynamic Response of Perovskite Solar CellsJun 12 2019Determination of the device performance parameters of perovskite solar cells is far from trivial as transient effects may cause large discrepancies in current-voltage measurements as a function of scan rate and pre-conditioning. Maximum power point tracking, ... More
Electronic and Optical Properties of Oligothiophene-F4TCNQ Charge-Transfer Complexes: The Role of Donor Conjugation LengthJun 12 2019We investigate from first-principles many-body theory the role of the donor conjugation length in doped organic semiconductors forming charge-transfer complexes (CTCs) exhibiting partial charge transfer. We consider oligothiophenes (nT) with an even number ... More
Unfolding the complexity of quasi-particle physics in disordered materialsJun 12 2019The concept of quasi-particles forms the theoretical basis of our microscopic understanding of emergent phenomena associated with quantum mechanical many-body interactions. However, quasi-particle theory in disordered materials has proven difficult, resulting ... More
Defect-Moderated Oxidative Etching of MoS2Jun 11 2019We report a simple technique for the selective etching of bilayer and monolayer MoS$_2$. In this work, chosen regions of MoS$_2$ were activated for oxygen adsorption and reaction by the application of low doses of He$^+$ at 30 keV in a gas ion microscope. ... More
Transfer matrix theory of surface spin echo experiments with moleculesJun 11 2019${}^3$He spin-echo experiments have been used to study surface morphology, molecular and atomic surface diffusion, phonon dispersions, phason dispersions and even phase transitions of ionic liquids. However, the interactions between ${}^3$He atoms and ... More
Van der Waals epitaxy of Mn-doped MoSe$_2$ on micaJun 11 2019The magnetic order associated with the degree of freedom of spin in two-dimensional (2D) materials is subjected to intense investigation because of its potential application in 2D spintronics and valley-related magnetic phenomena. We report here a bottom-up ... More
Bridging the Physics and Chemistry of graphene. From Huckel aromaticity to Dirac cones and topological insulatorsJun 11 2019By bridging graphene and benzene through a well-defined sequence of polycyclic aromatic hydrocarbons and their inherent shell structure, J. Phys. Chem. C, 2018, 122, 17526, it is shown that graphene is actually a coherent arrangement of interwoven benzene ... More
A Hybrid multiphase model based on lattice Boltzmann method direct simulationsJun 11 2019By means of the multicomponent Shan-Chen lattice Boltzmann method (LBM), we investigate the multiphase flow through porous media. Despite the excellent accuracy of the LBM, large domains result in unaffordable computational expenses. The Hybrid model ... More
A decade of skyrmionics: Writing, deleting, reading and processing magnetic skyrmions toward spintronic applicationsJun 11 2019Jun 12 2019The field of skyrmionics has been actively investigated across a wide range of topics during the last decade. In this topical review, we review and discuss key results and findings in skyrmionics since the first experimental observation of magnetic skyrmions ... More
A decade of skyrmionics: Writing, deleting, reading and processing magnetic skyrmions roward spintronic applicationsJun 11 2019The field of skyrmionics has been actively investigated across a wide range of topics during the last decade. In this topical review, we review and discuss key results and findings in skyrmionics since the first experimental observation of magnetic skyrmions ... More
Reliable Electrical Switching of Tri-State Antiferromagnetic Néel Order in $α$-Fe$_2$O$_3$ Epitaxial FilmsJun 11 2019The ability to manipulate antiferromagnetic (AF) moments is a key requirement for the emerging field of antiferromagnetic spintronics. Electrical switching of bi-state AF moments has been demonstrated in metallic AFs, CuMnAs and Mn$_2$Au. Recently, current-induced ... More
Characterisation of Li in the surface film of a corrosion resistant Mg-Li(-Al-Y-Zr) alloyJun 11 2019The surface film formed upon Mg-Li(-Al-Y-Zr) following aqueous immersion and air-exposure was investigated. This alloy (which contains 30.3 at. % Li) possesses a bcc crystal structure and has been reported as being corrosion resistant. It was determined ... More
Quantification model of X-ray fluorescence analysis based on iterative Monte Carlo procedureJun 11 2019Iterative Monte Carlo algorithm has been constructed and tested for quantification of X-ray fluorescence analysis in order to determine the atomic composition of solid materials. The calculation model uses simulation code MCNP6 that describes the excitation ... More
Towards Photoferroic Materials by Design: Recent Progresses and PerspectiveJun 11 2019The use of photoferroic materials that combine ferroelectric and light harvesting properties in a photovoltaic device is a promising route to significantly improve the efficiency of solar cells. These materials do not require the formation of a p-n junction ... More
Nonuniform quantum-confined states and visualization of hidden defects in thin Pb(111) filmsJun 11 2019The spatial distribution of the differential conductance for ultrathin Pb films grown on Si(111)7x7 substrate is studied by means of low-temperature scanning tunneling microscopy and spectroscopy. The formation of the quantum--confined states for conduction ... More
Tunneling interferometry and measurement of thickness of ultrathin metallic Pb(111) filmsJun 11 2019Spectra of the differential tunneling conductivity for ultrathin lead films grown on Si(111)7x7 single crystals with a thickness from 9 to 50 monolayers have been studied by low-temperature scanning tunneling microscopy and spectroscopy. The presence ... More
Proximity magnetoresistance in graphene induced by magnetic insulatorsJun 11 2019We demonstrate the existence of Giant proximity magnetoresistance (PMR) effect in a graphene spin valve where spin polarization is induced by a nearby magnetic insulator. PMR calculations were performed for yttrium iron garnet (YIG), cobalt ferrite (CFO), ... More
Observation of Large Unidirectional Rashba Magnetoresistance in Ge(111)Jun 11 2019Relating magnetotransport properties to specific spin textures at surfaces or interfaces is an intense field of research nowadays. Here, we investigate the variation of the electrical resistance of Ge(111) grown epitaxially on semi-insulating Si(111) ... More
Anisotropic Magnetoresistance and Nontrivial Spin Magnetoresistance in Pt/$α$-Fe$_2$O$_3$ Bilayers: Evidence for Antiferromagnetic Proximity EffectJun 11 2019To date, magnetic proximity effect (MPE) has only been conclusively observed in ferromagnet (FM) based systems. We report the observation of anomalous Hall effect and anisotropic magnetoresistance in angular dependent magnetoresistance (ADMR) measurements ... More
Magnetic Skyrmion State in Janus Monolayers of Chromium Trihalides Cr(I,X)3Jun 11 2019Magnetic skyrmions are nano-scale spin structures that is promising for ultradense memory and logic devices. Recent progresses in two-dimensional magnets encourage the idea to realize skyrmion state in monolayers, such as CrI$_3$. However, such magnet ... More
Many-body effects in strongly-disordered III-nitride quantum wells: interplay between carrier localization and Coulomb interactionJun 10 2019The joint impact of Anderson localization and many-body interaction is observed in the optical properties of strongly-disordered III-nitride quantum wells, a system where the Coulomb interaction and the fluctuating potential are pronounced effects with ... More
Linking morphology and thermal transport of asymmetric polymer blends by maromolecular engineeringJun 10 2019A grand challenge in designing polymeric materials is to tune their properties by macromolecular engineering. In this context, one of the drawbacks that often limits broader applications under high temperature conditions is their poor thermal conductivity ... More
Cation Disorder and Lithium Insertion Mechanism of Wadsley-Roth Crystallographic Shear PhasesJun 10 2019Wadsley-Roth crystallographic shear phases form a family of compounds that have attracted attention due to their excellent performance as lithium-ion battery electrodes. The complex crystallographic structure of these materials poses a challenge for first-principles ... More
Néel and stripe ordering from spin-orbital entanglement in $α$-Sr$_2$CrO$_4$Jun 10 2019The rich phenomenology engendered by the coupling between the spin and orbital degrees of freedom has become appreciated as a key feature of many strongly-correlated electron systems. The resulting emergent physics is particularly prominent in a number ... More
The crackling sound of stretching polycrystalline grapheneJun 10 2019Polycrystalline graphene has an inherent tendency to buckle, i.e. develop out-of-plane, three-dimensional structure. A force applied to stretch a piece of polycrystalline graphene influences the out-of-plane structure. Even if the graphene is well-relaxed, ... More
Assessing interface coupling in exchange-biased systems via in-field interaction plotsJun 10 2019An in-field interaction plot, $\delta M_{\rm R}$, has been recently introduced, presenting important advantages over the classical remanence plots. Here a general $\delta M_{\rm R}$ is proposed, allowing to assess interactions even in systems with shifted ... More
Thermal expansion coefficients of high thermal conducting BAs and BP materialsJun 10 2019Recent reported very high thermal conductivities in the cubic boron arsenide (BAs) and boron phosphide (BP) crystals could potentially provide a revolutionary solution in the thermal management of high power density devices. To fully facilitate such application, ... More
Mie Scattering of Phonons by Point Defects in IV-VI Semiconductors PbTe and GeTeJun 10 2019The scattering of thermal acoustic phonons by point defects in solids has been widely assumed the Rayleigh scattering type. In contrast to this conventional perception, using an ab initio Green's function approach, we show that the scattering by point ... More
Quantum oscillation of thermal conductivity and violation of Weidemann-Franz law in TaAs$_2$ and NbAs$_2$Jun 10 2019We report a study of thermal conductivity and resistivity at ultra-low temperatures and in high magnetic fields for semi-metal materials NbAs$_2$ and TaAs$_2$ by using single crystal samples. The thermal conductivity is strongly suppressed in magnetic ... More
Investigation of the electrostatic potential of a grain boundary in Y-substituted BaZrO3 using inline electron holographyJun 10 2019We apply inline electron holography to investigate the electrostatic potential across an individual BaZr0.9Y0.1O3 grain boundary. With holography, we measure a grain boundary potential of -1.3 V. Electron energy loss spectroscopy analyses indicate that ... More
Absorption and emission modulation in MoS2-GaN (0001) heterostructure by interface phonon-exciton couplingJun 10 2019Semiconductor heterostructures based on layered two-dimensional transition metal dichalcogenides (TMD) interfaced to gallium nitride (GaN) are excellent material systems to realize broadband light emitters and absorbers. The surface properties of the ... More
Trimer classical spin liquid from interacting fractional chargesJun 10 2019We study a problem of interacting fractional charges with $J_1$-$J_2$-$J_3$ Ising model on a checkerboard lattice under magnetic field. As a result of the interplay between repulsive interactions and particle density tuning by magnetic field, the fractional ... More
High Frequency Domain Wall Oscillations in Ferromagnetic Nanowire with a Nanoscale Dzyaloshinskii Moriya Interaction (DMI) RegionJun 10 2019The Dzyaloshinskii Moriya Interaction (DMI) has laid the foundation for many novel chiral structures such as Skyrmions. In most of the studies so far, the DMI is present in the whole of the magnetic layer. Here, we report our investigations on a ferromagnetic ... More
Successive Symmetry Breaking in a Jeff = 3/2 Quartet in the Spin-Orbit Coupled Insulator Ba2MgReO6Jun 10 2019We report on the cubic double perovskite Ba2MgReO6 containing Re6+ ions with the 5d1 electron configuration. Resistivity, magnetization, and heat capacity measurements using single crystals show that the compound is a Mott insulator with a magnetic transition ... More
Three-Dimensional Yielding in Anisotropic Materials: Validation of Hill CriterionJun 10 2019Yielding transition in isotropic soft materials under superposition of orthogonal deformation fields is known to follow von Mises criterion. However, in anisotropic soft materials von Mises criterion fails owing to preferred directions associated with ... More
Spin Seebeck effect in paramagnets and antiferromagnets at elevated temperaturesJun 10 2019We develop a theory of the spin Seebeck effect (SSE) in paramagnets as well as in antiferromagnets at elevated temperatures. Employing dissipative stochastic models that are valid at elevated temperatures, we calculate the SSE signal, and find that both ... More
Giant anisotropic magnetoresistance and nonvolatile memory in canted antiferromagnet Sr2IrO4Jun 10 2019Antiferromagnets have been generating intense interest in the spintronics community, owing to their intrinsic appealing properties like zero stray field and ultrafast spin dynamics. While the control of antiferromagnetic (AFM) orders has been realized ... More
Room Temperature Initialisation and Readout of Intrinsic Spin Defects in a Van der Waals CrystalJun 10 2019Optically addressable spins in widebandgap semiconductors have become one of the most prominent platforms for exploring fundamental quantum phenomena. While several candidates in 3D crystals including diamond and silicon carbide have been extensively ... More
Energetics and electronic structure of native point defects in $α$-Ga2O3Jun 10 2019We report first-principles calculations that clarify the formation energies and charge transition levels of native point defects (Ga and O vacancies, interstitials, and a Ga vacancy-O vacancy pair) in corundum structured ${\alpha}$-Ga2O3. Either under ... More
Spin dynamics and unconventional magnetism in insulating La$_{(1-2x)}$Sr$_{2x}$Co$_{(1-x)}$Nb$_{x}$O$_3$Jun 09 2019We study the structural, magnetic, transport and electronic properties of LaCoO$_3$ with Sr/Nb co-substitution, i.e., La$_{(1-2x)}$Sr$_{2x}$Co$_{(1-x)}$Nb$_{x}$O$_3$ using x-ray and neutron diffraction, dc and ac-magnetization, neutron depolarization, ... More
Elastic anomalies associated with domain switching in BaTiO$_3$ single crystals under in-situ electrical cyclingJun 09 2019The elastic response of BaTiO$_3$ single crystals during electric field cycling at room temperature has been studied using in-situ Resonant Ultrasound Spectroscopy (RUS), which allows monitoring of both the elastic and anelastic changes caused by ferroelectric ... More
Brittle-Ductile Transition in a Metallic GlassJun 08 2019Recent computational and laboratory experiments have shown that the brittle-ductile transition in metallic glasses such as Vitreloy-1 is strongly sensitive to the initial effective disorder (or ``fictive'') temperature. Glasses with lower effective temperatures ... More
Phononics of Graphene and Graphene CompositesJun 08 2019I present a concise account concerning the emergence of a research field, which deals with the thermal properties of graphene, covering the refinement of understanding of phonon transport in two-dimensional material systems. The practical application ... More
Multichannel remote polarization control enabled by nanostructured Liquid Crystalline NetworksJun 08 2019In this article we demonstrate that a grating fabricated through nanoscale volumetric crosslinking of a liquid crystalline polymer enables remote polarization control over the diffracted channels. This functionality is a consequence of the responsivity ... More
Road to Room-Temperature Superconductivity: Tc above 260 K in Lanthanum Superhydride under PressureJun 08 2019The use of high pressure to realize superconductivity in the vicinity of room temperature has a long history, much of it focused on achieving this in hydrogen rich materials. This paper provides a brief overview of the work presented at this May 2018 ... More
Metallic edge states in zig-zag vertically-oriented MoS2 nanowallsJun 08 2019The remarkable properties of layered materials such as MoS2 strongly depend on their dimensionality. Beyond manipulating their dimensions, it has been predicted that the electronic properties of MoS2 can also be tailored by carefully selecting the type ... More
The driving force behind the distortion of one-dimensional monatomic chains - Peierls theorem revisitedJun 08 2019The onset of distortion in one-dimensional monatomic chains with partially filled valence bands is considered to be well-established by the Peierls theorem, which associates the distortion with the formation of a band gap and a subsequent gain in energy. ... More
Insights on heterogeneity in blinking mechanisms and non-ergodicity using sub-ensemble statistical analysis of single quantum-dotsJun 08 2019Photo-luminescence intermittency (blinking) in semiconductor nanocrystals (NCs), a phenomenon ubiquitous to single-emitters, is generally considered to be temporally random intensity fluctuations between bright (On) and dark (Off) states. However, individual ... More
Possible emergence of a skyrmion phase in ferroelectric GaMo$_4$S$_8$Jun 08 2019Polar lacunar spinels, such as GaV$_4$S$_8$ and GaV$_4$Se$_8$, were proposed to host skyrmion phases under magnetic field. In this work, we put forward, as a candidate for N\'eel-type skyrmion lattice, the isostructural GaMo$_4$S$_8$, here systematically ... More
Transition to metallization in warm dense helium-hydrogen mixtures using stochastic density functional theory within the Kubo-Greenwood formalismJun 07 2019Abstract The Kubo-Greenwood (KG) formula is often used in conjunction with Kohn-Sham (KS) density functional theory (DFT) to compute the optical conductivity, particularly for warm dense mater. For applying the KG formula, all KS eigenstates and eigenvalues ... More
Ground States of Crystalline Caps: Generalized Jellium on Curved SpaceJun 07 2019Jun 11 2019We study the structure and elastic energy of the ground states of crystalline caps conforming to a spherical surface. These ground states consist of positive disclination defects in structures spanning from flat and weakly curved crystals to closed shells. ... More
Source Shot Noise Mitigation in Focused Ion Beam Microscopy by Time-Resolved MeasurementJun 07 2019Focused ion beam (FIB) microscopy suffers from source shot noise - random variation in the number of incident ions in any fixed dwell time - along with random variation in the number of detected secondary electrons per incident ion. This multiplicity ... More
Indirect but Efficient: Laser-Excited Electrons Can Drive Ultrafast Polarization Switching in Ferroelectric MaterialsJun 07 2019To enhance the efficiency of next-generation ferroelectric (FE) electronic devices, new techniques for controlling ferroelectric polarization switching are required. While most prior studies have attempted to induce polarization switching via the excitation ... More
Resonant Inelastic X-Ray Scattering in Metals: A Diagrammatic ApproachJun 07 2019We develop a formalism to study the Resonant Inelastic X-ray Scattering (RIXS) response in metals based on the diagrammatic expansion for its cross section. The standard approach to the solution of the RIXS problem relies on two key approximations: short-range ... More
Machine Learning Prediction of Accurate Atomization Energies of Organic Molecules from Low-Fidelity Quantum Chemical CalculationsJun 07 2019Recent studies illustrate how machine learning (ML) can be used to bypass a core challenge of molecular modeling: the tradeoff between accuracy and computational cost. Here, we assess multiple ML approaches for predicting the atomization energy of organic ... More
Tin Titanate: the hunt for a new ferroelectric perovskiteJun 07 2019We review all the published literature and show that there is no experimental evidence for homogeneous tin titanate SnTiO3 in bulk or thin-film form. Instead a combination of unrelated artefacts are easily misinterpreted. The X-ray Bragg data are contaminated ... More
Topological photocurrent responses from chiral surface Fermi arcsJun 07 2019The nonlinear optical responses from topological semimetals are crucial in both understanding the fundamental properties of quantum materials and designing next-generation light-sensors or solar-cells. However, previous work was focusing on the optical ... More
Chirality in the planeJun 07 2019It is well-known that many three-dimensional chiral material models become non-chiral when reduced to two dimensions. Chiral properties of the two-dimensional model can then be restored by adding appropriate two-dimensional chiral terms. In this paper ... More
Morphological and electrical properties of Nickel based Ohmic contacts formed by laser annealing process on n-type 4H-SiCJun 07 2019This work reports on the morphological and electrical properties of Ni-based back-side Ohmic contacts formed by laser annealing process for SiC power diodes. Nickel films, 100 nm thick, have been sputtered on the back-side of heavily doped 110 um 4H-SiC ... More
Multiscale modelling of the influence of hydrogen on dislocation junctions in bcc ironJun 07 2019Multiscale modelling of the influence of hydrogen on dislocation junctions is presented by incorporating a hydrogen core force into the total nodal force. The hydrogen core force arises due to hydrogen induced change in dislocation core energy, which ... More
Van der Waals solid phase epitaxy to grow large-area manganese-doped MoSe$_2$ few-layers on SiO$_2$/SiJun 07 2019Large-area growth of continuous transition metal dichalcogenides (TMDCs) layers is a prerequisite to transfer their exceptional electronic and optical properties into practical devices. It still represents an open issue nowadays. Electric and magnetic ... More
Magneto-spectroscopy of exciton Rydberg states in a CVD grown WSe2 monolayerJun 07 2019The results of magneto-optical spectroscopy investigations of excitons in a CVD grown monolayer of WSe2 encapsulated in hexagonal boron nitride are presented. The emission linewidth for the 1s state is of 4:7 meV, close to the narrowest emissions observed ... More
Strategy for enhanced thermoelectric performance of Bi2S3 nanorods by Bi nanoinclusionsJun 07 2019This is the first report on the enhanced thermoelectric (TE) properties of novel Bi2S3-Bi nanocomposites synthesized using a one-step polyol method at different reaction temperatures (TRe) and time. They are well-characterized as nanorod-composites, coexistent ... More
Influence of the electrode nano/microstructure on the electrochemical properties of graphite in aluminum batteriesJun 07 2019Herein we report on a detailed investigation of the irreversible capacity in the first cycle of pyrolytic graphite electrodes in aluminum batteries employing 1-ethyl-3-methylimidazolium chloride:aluminum trichloride (EMIMCl:AlCl3) as electrolyte. The ... More
Analytical description of the size effect on pyroelectric and electrocaloric properties of ferroelectric nanoparticlesJun 07 2019Using Landau-Ginzburg-Devonshire theory and effective medium approximation, we analytically calculate typical dependences of the pyroelectric and electrocaloric coefficients on external electric field, temperature and radius for spherical single-domain ... More
Topology optimization of unsaturated flows in multi-material porous media: application to a simple diaper modelJun 06 2019We present a mathematical approach to optimize the material distribution for fluid transport in unsaturated porous media. Our benchmark problem is a simplified diaper model as an exemplary liquid absorber. Our model has up to three materials with vastly ... More
Dynamic behavior of mechanical cloaks designed by direct lattice transformationJun 06 2019Steering waves in elastic solids is more demanding than steering waves in electromagnetism or acoustics. As a result, designing material distributions which are the counterpart of optical invisibility cloaks in elasticity poses a major challenge. Waves ... More
An Informatics Software Stack for Point Defect-Derived Opto-Electronic Properties: The Asphalt ProjectJun 06 2019Computational acceleration of performance-metric-based materials discovery via high-throughput screening and machine learning methods is becoming widespread. Nevertheless, development and optimization of the opto-electronic properties that depend on dilute ... More
Defect-induced magnetism and Yu-Shiba-Rusinov states in twisted bilayer grapheneJun 06 2019Atomic defects have a significant impact in the low-energy properties of graphene systems. By means of first-principles calculations and tight-binding models we provide evidence that chemical impurities modify both the normal and the superconducting states ... More
Foldable Cones as a Framework for Nonrigid OrigamiJun 06 2019The study of origami-based mechanical metamaterials usually focuses on the kinematics of deployable structures made of an assembly of rigid flat plates connected by hinges. When the elastic response of each panel is taken into account, novel behaviors ... More
Complete optical valley polarization in Weyl semimetals in strong magnetic fieldsJun 06 2019We present a theory of an optically induced valley polarization in an interacting, time-reversal symmetric Weyl semimetal placed under strong magnetic fields. Because the application of a magnetic field reduces the symmetry of the crystal, the optical ... More
Modeling the effect of microstructure on elastic wave propagation in platelet-reinforced composites and ceramicsJun 06 2019Dense ceramics are irreplaceable in applications requiring high mechanical stiffness, chemical and temperature resistance and low weight. To improve their toughness, ceramics can be reinforced with elongated inclusions. Recent manufacturing strategies ... More
Role of the exchange-correlation functional on the structural, electronic and optical properties of cubic and tetragonal SrTiO$_3$ including many-body effectsJun 06 2019SrTiO$_3$ is a model perovskite compound with unique properties and technological relevance. At 105 K it undergoes a transition from a cubic to a tetragonal phase with characteristic antiferrodistortive rotations of the TiO$_6$ octahedra. Here we study ... More
Role of Velocity Field and Principal Axis of Tilted Dirac Cones in Effective Hamlitonan of Non-Coplanar Nodal LoopJun 06 2019Nodal line in single-component molecular conductor [Pd(dddt)_2] has been examined to understand the tilted Dirac cone on the non-coplanar loop. In the previous work [J. Phys. Soc. Jpn. 87, 113701 (2018)], the velocity of the cone was calculated at respective ... More
Charactering the magnetic properties of the copper chalcopyrite semiconductor CuGaSe2 via Monte Carlo simulationsJun 06 2019This manuscript presents a model and simulation of the copper chalcopyrite semiconductor CuGaSe2 in order to predict its magnetic properties. In the semiconductor material CuGaSe2 (CGS), the atom Cu is the only magnetic element with a magnetic moment ... More
Discovery of Ionic Impact Ionization (I3) in Perovskites Triggered by a Single PhotonJun 06 2019Organic-inorganic metal halide perovskite devices have generated significant interest for LED, photodetector, and solar cell applications due to their attractive optoelectronic properties and substrate-choice flexibility1-4. These devices exhibit slow ... More
Electronic Band Structure of Cuprous and Silver Halides: a Numerically Accurate All-Electron $GW$ StudyJun 06 2019Group IB metal halides (CuX and AgX, X=Cl, Br and I) are widely used in optoelectronic devices and photochemical catalysis due to their appropriate optical and electronic properties. First-principles calculations have confronted difficulties in accurately ... More