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2023-12-07
Energy dissipation in astrophysical simulations: results of the Orszag-Tang test problem
The magnetic field through the magnetic reconnection process affects the dynamics and structure of astrophysical systems. Numerical simulations are the tools to study the evolution of these systems. However, the resolution, dimensions, resistivity, and turbulence of the system are some important parameters to take into...
2312.06675v1
2024-01-10
Some aspects of resistive-to-normal state transition by direct and microwave currents in superconducting thin films with phase slip lines
Based on analysis of current-voltage characteristics and imaging of the resistive state of thin-film tin strips using the low-temperature laser scanning microscopy (LTLSM), the process of destruction of superconductivity by current and microwave irradiation with the formation and spatial rearrangement of the order para...
2401.05333v1
2024-02-24
A simple model of globally magnetized accretion discs
We present an analytic, quasi-local dynamo model for accretion discs threaded by net, vertical magnetic flux. In a simple slab geometry and ignoring stochastic mean-field dynamo effects, we calculate the large-scale field resulting from the balance between kinematic field amplification and turbulent resistive diffusion...
2402.15657v1
2024-02-28
Stability studies of sealed Resistive Plate Chambers
The phase-out of hydro-fluorocarbons, owing to their high Global Warming Power, affecting the main gas used in Resistive Plate Chambers (RPCs), tetrafluoroethane C$_2$H$_2$F$_4$, has increased operational difficulties on existing systems and imposes strong restrictions on its use in new systems. This has motivated a ...
2402.18663v1
2024-03-06
Foot Shape-Dependent Resistive Force Model for Bipedal Walkers on Granular Terrains
Legged robots have demonstrated high efficiency and effectiveness in unstructured and dynamic environments. However, it is still challenging for legged robots to achieve rapid and efficient locomotion on deformable, yielding substrates, such as granular terrains. We present an enhanced resistive force model for bipedal...
2403.03460v1
2024-03-13
Lithographically Defined Zerogap Strain Sensors
Metal thin films on soft polymers provide a unique opportunity for resistance-based strain sensors. A mechanical mismatch between the conductive film and the flexible substrate causes cracks to open and close, changing the electrical resistance as a function of strain. However, the very randomness of the formation, sha...
2403.08288v1
2024-03-19
Revisiting shear stress tensor evolution: Non-resistive magnetohydrodynamics with momentum-dependent relaxation time
This study aims to develop second-order relativistic viscous magnetohydrodynamics (MHD) derived from kinetic theory within an extended relaxation time approximation (momentum/energy dependent) for the collision kernel. The investigation involves a detailed examination of shear stress tensor evolution equations and asso...
2403.13160v2
2024-03-20
Experience gained about Resistive Plate Chambers ageing from the ALICE Muon TRigger/IDentifier detector
The ALICE Muon IDentifier is composed of 72 single-gap bakelite Resistive Plate Chambers, which have been operational since 2009 in maxi-avalanche mode (discrimination threshold:7 mV without amplification) with a Tetrafluoroethane/Isobutane/Sulfur Hexafluoride gas mixture, undergoing counting rates of the order of tens...
2403.13618v1
2024-03-25
Improving Diffusion Models's Data-Corruption Resistance using Scheduled Pseudo-Huber Loss
Diffusion models are known to be vulnerable to outliers in training data. In this paper we study an alternative diffusion loss function, which can preserve the high quality of generated data like the original squared $L_{2}$ loss while at the same time being robust to outliers. We propose to use pseudo-Huber loss funct...
2403.16728v1
2024-04-01
Giant and negative magnetoresistances in conical magnets
We study magnetotransport in conical helimagnet crystals. Spin dependent magnetoresistance exhibits dramatic properties for high and low electron concentrations at different temperatures. For spin up electrons we find negative magnetoresistance despite only considering a single carrier type. For spin down electrons we ...
2404.01401v1
2024-04-02
Integer and fractional quantum anomalous Hall effects in pentalayer graphene
We critically analyze the recently reported observation of integer (IQAHE) and fractional (FQAHE) quantum anomalous Hall effects at zero applied magnetic field in pentalayer graphene. Our quantitative activation and variable range hopping transport analysis of the experimental data reveals that the observed IQAHE and F...
2404.02192v1
2024-05-06
Polynomial lower bound on the effective resistance for the one-dimensional critical long-range percolation
In this work, we study the critical long-range percolation on $\mathbb{Z}$, where an edge connects $i$ and $j$ independently with probability $1-\exp\{-\beta |i-j|^{-2}\}$ for some fixed $\beta>0$. Viewing this as a random electric network where each edge has a unit conductance, we show that with high probability the e...
2405.03460v1
2018-09-07
Mapping the depleted area of silicon diodes using a micro-focused X-ray beam
For the Phase-II Upgrade of the ATLAS detector at CERN, the current ATLAS Inner Detector will be replaced with the ATLAS Inner Tracker. The ATLAS Inner Tracker will be an all-silicon detector, consisting of a pixel tracker and a strip tracker. Sensors for the ITk strip tracker are required to have a low leakage current...
1809.02667v2
2020-02-28
Accelerating and Stopping Resistance Drift in Phase Change Memory Cells via High Electric Field Stress
We observed resistance drift in 125 K - 300 K temperature range in melt quenched amorphous Ge2Sb2Te5 line-cells with length x width x thickness = ~500 nm x ~100 nm x ~ 50 nm. Drift coefficients measured using small voltage sweeps appear to decrease from 0.12 +/- 0.029 at 300 K to 0.075 +/- 0.006 at 125 K. The current-v...
2002.12487v1
2021-10-18
Negative differential resistance state in the free-flux-flow regime of driven vortices in a single crystal of 2H-NbS$_2$
Time series measurements in 2H-NbS$_2$ crystal had unravelled a drive induced transition wherein the critical current (Ic) changes from a low to a high Ic jammed vortex state, via a negative differential resistance (NDR) transition. Here, using multiple current (I) - voltage (V) measurement cycles, we explore the stati...
2110.09379v2
2020-11-28
Development of polar nematic fluids with giant-\k{appa} dielectric properties
Super-high-\k{appa} materials that exhibit exceptionally high dielectric permittivity are recognized as potential candidates for a wide range of next-generation photonic and electronic devices. Generally, the high dielectricity for achieving a high-\k{appa} state requires a low symmetry of materials so that most of the...
2011.14099v1
2019-02-26
The Evidence of Cathodic Micro-discharges during Plasma Electrolytic Oxidation Process
Plasma electrolytic oxidation (PEO) processing of EV 31 magnesium alloy has been carried out in fluoride containing electrolyte under bipolar pulse current regime. Unusual PEO cathodic micro-discharges have been observed and investigated. It is shown that the cathodic micro-discharges exhibit a collective intermittent ...
1902.09828v1
2019-07-05
Materials databases: the need for open, interoperable databases with standardized data and rich metadata
Driven by the recent rapid increase in the number of materials databases published (open and commercial), I discuss here some perspectives on the growing need for standardized, interoperable, open databases. The field of computational materials discovery is quickly expanding, and recent advances in data mining, high th...
1907.02791v1
2016-01-07
First principles search for $n$-type oxide, nitride, and sulfide thermoelectrics
Oxides have many potentially desirable characteristics for thermoelectric applications, including low cost and stability at high temperatures, but thus far there are few known high $zT$ $n$-type oxide thermoelectrics. In this work, we use high-throughput first principles calculations to screen transition metal oxides, ...
1601.01622v2
2014-09-03
Mechanics of freely-suspended ultrathin layered materials
The study of atomically thin two-dimensional materials is a young and rapidly growing field. In the past years, a great advance in the study of the remarkable electrical and optical properties of 2D materials fabricated by exfoliation of bulk layered materials has been achieved. Due to the extraordinary mechanical prop...
1409.1173v2
2015-01-18
Ultra-high mechanical stretchability and controllable topological phase transitions in two-dimensional arsenic
The mechanical stretchability is the magnitude of strain which a material can suffer before it breaks. Materials with high mechanical stretchability, which can reversibly withstand extreme mechanical deformation and cover arbitrary surfaces and movable parts, are used for stretchable display devices, broadband photonic...
1501.04350v1
2022-04-02
Inventory of high-quality flat-band van der Waals materials
More is left to do in the field of flat bands besides proposing theoretical models. One unexplored area is the flat bands featured in the van der Waals (vdW) materials. Exploring more flat-band material candidates and moving the promising materials toward applications have been well recognized as the cornerstones for t...
2204.00810v1
2017-02-25
Electronic conduction properties of indium tin oxide: single-particle and many-body transport
Indium tin oxide (Sn-doped In$_2$O$_{3-\delta}$ or ITO) is an interesting and technologically important transparent conducting oxide. This class of material has been extensively studied for decades, with research efforts focusing on the application aspects. The fundamental issues of the electronic conduction properties...
1702.07845v1
2018-06-11
Coincident Molecular Auxeticity and Negative Order Parameter in a Liquid Crystal Elastomer
"Auxetic" materials have the counter-intuitive property of expanding rather than contracting perpendicular to an applied stretch, formally they have negative Poisson's Ratios (PRs).[1,2] This results in properties such as enhanced energy absorption and indentation resistance, which means that auxetics have potential fo...
1807.03608v1
2022-05-11
Effect of magnetic phase coexistence on spin-phonon coupling and magnetoelectric effect in polycrystalline Sm0.5Y0.5Fe0.58Mn0.42O3
The polycrystalline co-doped samples of Sm0.5Y0.5Fe0.58Mn0.42O3 were prepared by solid-state reaction route and its various physical properties with their correlations have been investigated. The dc magnetization measurements on the sample revealed a weak ferromagnetic (WFM) transition at TN=361 K that is followed by a...
2205.05291v2
2023-08-18
Magnon Diffusion Length and Longitudinal Spin Seebeck Effect in Vanadium Tetracyanoethylene (V[TCNE]$_x$, $x \sim 2$)
Spintronic, spin caloritronic, and magnonic phenomena arise from complex interactions between charge, spin, and structural degrees of freedom that are challenging to model and even more difficult to predict. This situation is compounded by the relative scarcity of magnetically-ordered materials with relevant functional...
2308.09752v1
1998-08-25
Unconventional Transition from Metallic to Insulating Resistivity in the Spin-ladder Compound (Sr,Ca)$_{14}$Cu$_{24}$O$_{41}$
Spin-ladder compounds make interesting analogs of the high-temperature superconductors, because they contain layers of nearly one-dimensional "ladders" consisting of a square array of copper and oxygen atoms. Increasing the number of legs in the ladders provides a step-wise approach toward the two-dimensional copper-ox...
9808284v2
2000-02-17
Effect of Magnetic field on the Pseudogap Phenomena in High-Tc Cuprates
We theoretically investigate the effect of magnetic field on the pseudogap phenomena in High-Tc cuprates. The obtained results well explain the experimental results including their doping dependences. In our previous paper (J. Phys. Soc. Jpn. 68 (1999) 2999.), we have shown that the pseudogap phenomena observed in ...
0002274v1
2018-11-15
High Kinetic Inductance Microwave Resonators Made by He-Beam Assisted Deposition of Tungsten Nanowires
We evaluate the performance of hybrid microwave resonators made by combining sputtered Nb thin films with Tungsten nanowires grown with a He-beam induced deposition technique. Depending on growth conditions the nanowires have a typical width $w\in[35-75]$~nm and thickness $t\in[5-40]$~nm. We observe a high normal state...
1811.06496v2
2017-05-16
Scale-invariant magnetoresistance in a cuprate superconductor
The anomalous metallic state in high-temperature superconducting cuprates is masked by the onset of superconductivity near a quantum critical point. Use of high magnetic fields to suppress superconductivity has enabled a detailed study of the ground state in these systems. Yet, the direct effect of strong magnetic fiel...
1705.05806v2
2022-11-22
Development of ultra-low mass and high-rate capable RPC based on Diamond-Like Carbon electrodes for MEG II experiment
A new type of resistive plate chamber with thin-film electrodes based on diamond-like carbon is under development for background identification in the MEG II experiment. Installed in a low-momentum and high-intensity muon beam, the detector is required to have extremely low mass and a high rate capability. A single-lay...
2211.12172v2
2010-05-05
Review of Best Practice Methods for Determining an Electrode Material's Performance for Ultracapacitors
Ultracapacitors are rapidly being adopted for use for a wide range of electrical energy storage applications. While ultracapacitors are able to deliver high rates of charge and discharge, they are limited in the amount of energy stored. The capacity of ultracapacitors is largely determined by the electrode material and...
1005.0805v2
2016-07-22
How to Characterize Thermal Transport Capability of 2D Materials Fairly? - Sheet Thermal Conductance and the Choice of Thickness
Ever since the discovery of the record-high thermal conductivity of single layer graphene, thermal transport capability of monolayer 2D materials has been under constant spotlight. Since thermal conductivity is an intensive property for 3D materials and the thickness of 2D materials is not well defined, different defin...
1607.06542v2
2018-02-05
Plasmonic physics of 2D crystalline materials
Collective modes of doped two-dimensional crystalline materials, namely graphene, MoS$_2$ and phosphorene, both monolayer and bilayer structures, are explored using the density functional theory simulations together with the random phase approximation. The many-body dielectric functions of the materials are calculated ...
1802.01291v1
2018-07-01
Correlated materials design: prospects and challenges
The design of correlated materials challenges researchers to combine the maturing, high throughput framework of DFT-based materials design with the rapidly-developing first-principles theory for correlated electron systems. We review the field of correlated materials, distinguishing two broad classes of correlation eff...
1807.00398v2
2020-05-09
Learning Properties of Ordered and Disordered Materials from Multi-fidelity Data
Predicting the properties of a material from the arrangement of its atoms is a fundamental goal in materials science. While machine learning has emerged in recent years as a new paradigm to provide rapid predictions of materials properties, their practical utility is limited by the scarcity of high-fidelity data. Here,...
2005.04338v3
2020-08-24
Inverse Design of Composite Metal Oxide Optical Materials based on Deep Transfer Learning
Optical materials with special optical properties are widely used in a broad span of technologies, from computer displays to solar energy utilization leading to large dataset accumulated from years of extensive materials synthesis and optical characterization. Previously, machine learning models have been developed to ...
2008.10618v1
2022-04-04
Hole-doping induced ferromagnetism in 2D materials
Two-dimensional (2D) ferromagnetic materials are considered as promising candidates for the future generations of spintronic devices. Yet, 2D materials with intrinsic ferromagnetism are scarce. High-throughput first-principles simulations are performed in order to screen 2D materials that present a non-magnetic to a fe...
2204.01551v2
2023-03-29
A Comprehensive and Versatile Multimodal Deep Learning Approach for Predicting Diverse Properties of Advanced Materials
We present a multimodal deep learning (MDL) framework for predicting physical properties of a 10-dimensional acrylic polymer composite material by merging physical attributes and chemical data. Our MDL model comprises four modules, including three generative deep learning models for material structure characterization ...
2303.16412v1
2024-04-03
Construction of Functional Materials Knowledge Graph in Multidisciplinary Materials Science via Large Language Model
The convergence of materials science and artificial intelligence has unlocked new opportunities for gathering, analyzing, and generating novel materials sourced from extensive scientific literature. Despite the potential benefits, persistent challenges such as manual annotation, precise extraction, and traceability iss...
2404.03080v1
2024-04-09
Deep-Learning Database of Density Functional Theory Hamiltonians for Twisted Materials
Moir\'e-twisted materials have garnered significant research interest due to their distinctive properties and intriguing physics. However, conducting first-principles studies on such materials faces challenges, notably the formidable computational cost associated with simulating ultra-large twisted structures. This obs...
2404.06449v1
2020-03-15
New quantum phases of matter: Topological Materials
In this article, we provide an overview of the basic concepts of novel topological materials. This new class of materials developed by combining the Weyl/Dirac fermionic electron states and magnetism, provide a materials-science platform to test predictions of the laws of topological physics. Owing to their dissipation...
2003.06835v1
2019-06-11
Towards Photoferroic Materials by Design: Recent Progresses and Perspective
The 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 and can produce photovoltages well above the value of the band...
1906.04490v1
2023-11-06
Cross-Plane Thermal Transport in Layered Materials
The cross-plane (across-layers) phonon thermal transport of five diverse, layered semiconductors is investigated by accounting for higher-order four-phonon scattering, phonon renormalization, and multi-channel thermal transport. For materials having relatively large cross-plane thermal conductivity (AlB6, MoS2, and MoS...
2311.03144v1
2024-03-15
MADAS -- A Python framework for assessing similarity in materials-science data
Computational materials science produces large quantities of data, both in terms of high-throughput calculations and individual studies. Extracting knowledge from this large and heterogeneous pool of data is challenging due to the wide variety of computational methods and approximations, resulting in significant veraci...
2403.10470v1
2017-02-18
Tunable Hyperbolic Dispersion and Negative Refraction in Natural Electride Materials
Hyperbolic (or indefinite) materials have attracted significant attention due to their unique capabilities for engineering electromagnetic space and controlling light propagation. A current challenge is to find a hyperbolic material with wide working frequency window, low energy loss, and easy controllability. Here, we...
1702.05602v1
2018-04-23
Gaussian Material Synthesis
We present a learning-based system for rapid mass-scale material synthesis that is useful for novice and expert users alike. The user preferences are learned via Gaussian Process Regression and can be easily sampled for new recommendations. Typically, each recommendation takes 40-60 seconds to render with global illumi...
1804.08369v1
2022-02-10
Topogivity: A Machine-Learned Chemical Rule for Discovering Topological Materials
Topological materials present unconventional electronic properties that make them attractive for both basic science and next-generation technological applications. The majority of currently known topological materials have been discovered using methods that involve symmetry-based analysis of the quantum wavefunction. H...
2202.05255v3
2021-09-11
Highly Accurate, Reliable and Non-Contaminating Two-Dimensional Material Transfer System
The exotic properties of two-dimensional (2D) materials and 2D heterostructures, built by forming heterogeneous multi-layered stacks, have been widely explored across a number of subject matters following the goal to invent, design, and improve applications enabled by 2D materials. To successfully harvest these unique ...
2109.05158v2
2021-11-10
Piezoelectric modulus prediction using machine learning and graph neural networks
Piezoelectric materials are widely used in all kinds of industries such as electric cigarette lighters, diesel engines and x-ray shutters. However, discovering high-performance and environmentally friendly (e.g. lead-free) piezoelectric materials is a difficult problem due to the sophisticated relationships from materi...
2111.05557v1
2023-06-25
Discovering two-dimensional magnetic topological insulators by machine learning
Topological materials with unconventional electronic properties have been investigated intensively for both fundamental and practical interests. Thousands of topological materials have been identified by symmetry-based analysis and ab initio calculations. However, the predicted magnetic topological insulators with genu...
2306.14155v2
2023-10-21
Advances in Complex Oxide Quantum Materials Through New Approaches to Molecular Beam Epitaxy
Molecular beam epitaxy (MBE), a workhorse of the semiconductor industry, has progressed rapidly in the last few decades in the development of novel materials. Recent developments in condensed matter and materials physics have seen the rise of many novel quantum materials that require ultra-clean and high-quality sample...
2310.13902v1
2002-05-31
Structure and Superconductivity in Zr-Stabilized, Nonstoichiometric Molybdenum Diboride
The structure and physical properties of the Zr-stabilized, nonstoichiometric molybdenum diboride superconductor are reported. Good quality material of the diboride structure type can only be obtained by partial substitution of Zr for Mo, and the quenching of melts. The phase is best made with boron in excess of the id...
0206006v1
2003-07-31
The break up of heavy electrons at a quantum critical point
The point at absolute zero where matter becomes unstable to new forms of order is called a quantum critical point (QCP). The quantum fluctuations between order and disorder that develop at this point induce profound transformations in the finite temperature electronic properties of the material. Magnetic fields are ide...
0308001v1
2006-06-16
Multiferroic tunnel junctions
Multiferroics are singular materials that can display simultaneously electric and magnetic orders. Some of them can be ferroelectric and ferromagnetic and, for example, provide the unique opportunity of encoding information independently in electric polarization and magnetization to obtain four different logic states. ...
0606444v1
2006-10-29
Detection of Individual Gas Molecules Absorbed on Graphene
The ultimate aspiration of any detection method is to achieve such a level of sensitivity that individual quanta of a measured value can be resolved. In the case of chemical sensors, the quantum is one atom or molecule. Such resolution has so far been beyond the reach of any detection technique, including solid-state g...
0610809v2
2007-11-26
Experimental investigation on the microscopic structure of intrinsic paramagnetic point defects in amorphous silicon dioxide
In the present Ph.D. Thesis we report an experimental investigation on the effects of gamma- and beta-ray irradiation and of subsequent thermal treatment on many types of a-SiO2 materials, differing in the production methods, OH- and Al-content, and oxygen deficiencies. Our main objective is to gain further insight on ...
0711.4029v1
2011-06-16
The Memory-Conservation Theory of Memristance
The memristor, the recently discovered fundamental circuit element, is of great interest for neuromorphic computing, nonlinear electronics and computer memory. It is usually modelled either using Chua's equations, which lack material device properties, or using Strukov's phenomenological model (or models derived from i...
1106.3170v3
2012-04-18
Controlling bulk conductivity in topological insulators: Key role of anti-site defects
The binary Bi-chalchogenides, Bi2Ch3, are widely regarded as model examples of a recently discovered new form of quantum matter, the three-dimensional topological insulator (TI) [1-4]. These compounds host a single spin-helical surface state which is guaranteed to be metallic due to time reversal symmetry, and should b...
1204.4063v1
2013-09-12
Theoretical Field Limits for Multi-Layer Superconductors
The SIS structure---a thin superconducting film on a bulk superconductor separated by a thin insulating film---was propsed as a method to protect alternative SRF materials from flux penetration by enhancing the first critical field $B_{c1}$. In this work, we show that in fact $B_{c1}$ = 0 for a SIS structure. We calcul...
1309.3239v2
2014-07-08
Competing magnetic phases and field-induced dynamics in DyRuAsO
Analysis of neutron diffraction, dc magnetization, ac magnetic susceptibility, heat capacity, and electrical resistivity for DyRuAsO in an applied magnetic field are presented at temperatures near and below those at which the structural distortion (T_S = 25 K) and subsequent magnetic ordering (T_N = 10.5 K) take place....
1407.2184v1
2014-07-13
Gate-tunable Phase Transitions in 1T-TaS$_2$
The ability to tune material properties using gate electric field is at the heart of modern electronic technology. It is also a driving force behind recent advances in two-dimensional systems, such as gate-electric-field induced superconductivity and metal-insulator transition. Here we describe an ionic field-effect tr...
1407.3480v1
2014-12-16
Characterization of 3 mm Glass Electrodes and Development of RPC Detectors for $INO-ICAL$ Experiment
India-based Neutrino Observatory (INO) is a multi-institutional facility, planned to be built up in South India. The INO facility will host a 51 kton magnetized Iron CALorimeter (ICAL) detector to study atmospheric muon neutrinos. Iron plates have been chosen as the target material whereas Resistive Plate Chambers (RPC...
1412.4998v1
2015-12-07
Insulating phase in Sr$_2$IrO$_4$: An investigation using critical analysis and magnetocaloric effect
The nature of insulating phase in 5$d$ based Sr$_2$IrO$_4$ is quite debated as the theoretical as well as experimental investigations have put forward evidences in favor of both magnetically driven Slater-type and interaction driven Mott-type insulator. To understand this insulating behavior, we have investigated the n...
1512.02041v1
2016-02-04
Picosecond electric-field-induced threshold switching in phase-change materials
Many chalcogenide glasses undergo a breakdown in electronic resistance above a critical field strength. Known as threshold switching, this mechanism enables field-induced crystallization in emerging phase-change memory. Purely electronic as well as crystal nucleation assisted models have been employed to explain the el...
1602.01885v2
2016-10-17
Structural, magnetic, electric, dielectric, and thermodynamic properties of multiferroic GeV4S8
The lacunar spinel GeV4S8 undergoes orbital and ferroelectric ordering at the Jahn-Teller transition around 30 K and exhibits antiferromagnetic order below about 14 K. In addition to this orbitally driven ferroelectricity, lacunar spinels are an interesting material class, as the vanadium ions form V4 clusters represen...
1610.05244v1
2017-02-15
Negative Differential Resistance in Graphene Boron Nitride Heterostructure Controlled by Twist and Phonon-Scattering
Two-dimensional (2D) crystals, such as graphene, hexagonal boron nitride and transitional metal dichalcogenides, have attracted tremendous amount of attention over the past decade due to their extraordinary thermal, electrical and optical properties, making them promising nano-materials for the next-generation electron...
1702.04435v1
2017-09-12
Electric field induced semiconductor-to-metal phase transition in vertical MoTe2 and Mo1-xWxTe2 devices
Over the past years, transition metal dichalcogenides (TMDs) have attracted attention as potential building blocks for various electronic applications due to their atomically thin nature. An exciting development is the recent success in 'engineering' crystal phases of TMD compounds during the growth due to their polymo...
1709.03835v1
2018-01-05
Writing on Nanocrystals: Patterning Colloidal Inorganic Nanocrystal Films through Irradiation-Induced Chemical Transformations of Surface Ligands
In the past couple of decades, colloidal inorganic nanocrystals and, more specifically, semiconductor quantum dots have emerged as crucial materials for the development of nanoscience and nanotechnology, with applications in very diverse areas such as optoelectronics and biotechnology. Films made of inorganic NCs depos...
1801.01756v1
2018-04-09
Pressure effects on the structural and superconducting transitions in La3Co4Sn13
La3Co4Sn13 is a superconducting material with transition temperature at Tc = 2.70 K, which presents a superlattice structural transition at T* ~ 150 K, a common feature for this class of compounds. However, for this material, it is not clear that at T* the lattice distortions arise from a charge density wave (CDW) or f...
1804.03215v2
2018-06-14
Tunneling spin valves based on Fe$_3$GeTe$_2$/hBN/Fe$_3$GeTe$_2$ van der Waals heterostructures
Thin van der Waals (vdW) layered magnetic materials disclose the possibility to realize vdW heterostructures with new functionalities. Here we report on the realization and investigation of tunneling spin valves based on van der Waals heterostructures consisting of an atomically thin hBN layer acting as tunnel barrier ...
1806.05411v1
2018-06-18
Mott transition and collective charge pinning in electron doped Sr2IrO4
We studied the in-plane dynamic and static charge conductivity of electron doped Sr2IrO4 using optical spectroscopy and DC transport measurements. The optical conductivity indicates that the pristine material is an indirect semiconductor with a direct Mott-gap of 0.55 eV. Upon substitution of 2% La per formula unit the...
1806.06937v1
2018-06-22
Disorder control in crystalline GeSb2Te4 and its impact on characteristic length scales
Crystalline GeSb2Te4 (GST) is remarkable material, as it allows to continuously tune the electrical resistance by orders of magnitude without involving a phase transition or stoichiometric changes, just by altering the short-range order. While well-ordered specimen are metallic, increasing amounts of disorder can event...
1806.08636v1
2019-09-26
Large-area implementation and critical evaluation of the material and fabrication aspects of a thin-film thermoelectric generator based on aluminum-doped zinc oxide
A large-area thermoelectric generator (TEG) utilizing a folded thin-film concept is implemented and the performance evaluated for near room temperature applications having modest temperature gradients (< 50 K). The TEGs with the area of ~0.33 m^2 are shown capable of powering a wireless sensor node of multiple sensors ...
1909.12042v2
2019-09-26
Quantum effects in graphitic materials: Colossal magnetoresistance, Andreev reflections, Little-Parks effect, ferromagnetism, and granular superconductivity
Unlike the more common local conductance spectroscopy, nonlocal conductance can differentiate between nontopological zero-energy modes localized around inhomogeneities, and true Majorana edge modes in the topological phase. In particular, negative nonlocal conductance is dominated by the crossed Andreev reflection. In ...
1909.12145v1
2015-05-18
Photoemission System with Polarized Hard X-rays for Probing Ground State Symmetry of Strongly Correlated Materials
We have developed a polarized hard X-ray photoemission (HAXPES) system to study the ground-state symmetry of strongly correlated materials. The linear polarization of the incoming X-ray beam is switched by the transmission-type phase retarder composed of two diamond (100) crystals. The best degree of the linear polariz...
1505.04591v1
2017-01-02
Thermoelectric power factor enhancement by spin-polarized currents - a nanowire case study
Thermoelectric (TE) measurements have been performed on the workhorses of today's data storage devices, exhibiting either the giant or the anisotropic magnetoresistance effect (GMR and AMR). The temperature-dependent (50-300 K) and magnetic field-dependent (up to 1 T) TE power factor (PF) has been determined for severa...
1701.00404v1
2018-11-20
Towards integrated metatronics: a holistic approach on precise optical and electrical properties of Indium Tin Oxide
The class of transparent conductive oxides includes the material indium tin oxide (ITO) and has become a widely used material of modern every-day life such as in touch screens of smart phones and watches, but also used as an optically transparent low electrically-resistive contract in the photovoltaics industry. More r...
1811.08344v4
2018-11-30
Thermal Transport Across Graphene Step Junctions
Step junctions are often present in layered materials, i.e. where single-layer regions meet multi-layer regions, yet their effect on thermal transport is not understood to date. Here, we measure heat flow across graphene junctions (GJs) from monolayer to bilayer graphene, as well as bilayer to four-layer graphene for t...
1811.12622v1
2019-05-29
Physical mechanisms involved in the formation and operation of memory devices based on a monolayer of gold nanoparticles-polythiophene hybrid materials
Understanding the physical and chemical mechanisms occurring during the forming process and operation of an organic resistive memory device is a major issue for better performances. Various mechanisms were suggested in vertically stacked memory structures, but the analysis remains indirect and needs destructive charact...
1905.12719v1
2020-03-25
Synergistically creating sulfur vacancies in semimetal-supported amorphous MoS2 for efficient hydrogen evolution
The presence of elemental vacancies in materials is inevitable according to statistical thermodynamics, which will decide the chemical and physical properties of the investigated system. However, the controlled manipulation of vacancies for specific applications is a challenge. Here we report a facile method for creati...
2003.11436v1
2020-04-01
Physical properties and thermal stability of Fe5GeTe2 single crystals
The magnetic and transport properties of Fe-deficient Fe5GeTe2 single crystals (Fe5-xGeTe2 with x~0.3) were studied and the impact of thermal processing was explored. Quenching crystals from the growth temperature has been previously shown to produce a metastable state that undergoes a strongly hysteretic first-order t...
2004.00494v1
2020-04-14
Photoanodes Based on TiO$_2$ and $α$-Fe$_2$O$_3$ for Solar Water Splitting Superior Role of 1D Nanoarchitectures and of Combined Heterostructures
Solar driven photoelectrochemical water splitting (PEC-WS) using semiconductor photoelectrodes represents a promising approach for a sustainable and environmentally friendly production of renewable energy vectors and fuel sources, such as dihydrogen (H2). In this context, titanium dioxide (TiO$_2$) and iron oxide (hema...
2004.12844v1
2007-10-08
Colossal dielectric constants in single-crystalline and ceramic CaCu3Ti4O12 investigated by broadband dielectric spectroscopy
In the present work the authors report results of broadband dielectric spectroscopy on various samples of CaCu3Ti4O12, including so far only rarely investigated single crystalline material. The measurements extend up to 1.3 GHz, covering more than nine frequency decades. We address the question of the origin of the col...
0710.1610v1
2017-04-13
Extreme Magnetoresistance in Magnetic Rare Earth Monopnictides
The acute sensitivity of the electrical resistance of certain systems to magnetic fields known as extreme magnetoresistance (XMR) has recently been explored in a new materials context with topological semimetals. Exemplified by WTe$_{2}$ and rare earth monopnictide La(Sb,Bi), these systems tend to be non-magnetic, near...
1704.04226v1
2018-08-28
Mott metal-insulator transitions in pressurized layered trichalcogenides
Transition metal phosphorous trichalcogenides, $M{\rm P}X_3$ ($M$ and $X$ being transition metal and chalcogen elements respectively), have been the focus of substantial interest recently because of their possible magnetism in the two-dimensional limit. Here we investigate material properties of the compounds with $M$ ...
1808.09263v2
2019-03-01
Unraveling Bulk and Grain Boundary Electrical Properties in La0.8Sr0.2Mn1-yO3 Thin Films
Grain boundaries in Sr-doped LaMnO3 thin films have been shown to strongly influence the electronic and oxygen mass transport properties, being able to profoundly modify the nature of the material. The unique behaviour of the grain boundaries can be correlated with substantial modifications of the cation concentration ...
1903.00235v1
2019-04-12
Spin-dependent transport in van der Waals magnetic tunnel junctions with Fe3GeTe2 electrodes
Van der Waals (vdW) heterostructures, stacking different two-dimensional materials, have opened up unprecedented opportunities to explore new physics and device concepts. Especially interesting are recently discovered two-dimensional magnetic vdW materials, providing new paradigms for spintronic applications. Here, usi...
1904.06098v1
2019-12-13
Shallow impurity band in ZrNiSn
ZrNiSn and related half Heusler compounds are candidate materials for efficient thermoelectric energy conversion with a reported thermoelectric figure-of-merit of n-type ZrNiSn exceeding unity. Progress on p-type materials has been more limited, which has been attributed to the presence of an impurity band, possibly re...
1912.06539v1
2020-12-23
A general theory for anisotropic Kirchhoff-Love shells with in-plane bending of embedded fibers
This work presents a generalized Kirchhoff-Love shell theory that can explicitly capture fiber-induced anisotropy not only in stretching and out-of-plane bending, but also in in-plane bending. This setup is particularly suitable for heterogeneous and fibrous materials such as textiles, biomaterials, composites and pant...
2101.03122v3
2012-03-06
Discrete modelling of capillary mechanisms in multi-phase granular media
A numerical study of multi-phase granular materials based upon micro-mechanical modelling is proposed. Discrete element simulations are used to investigate capillary induced effects on the friction properties of a granular assembly in the pendular regime. Capillary forces are described at the local scale through the Yo...
1203.1234v1
2015-06-12
Current-limiting challenges for all-spin logic devices
All-spin logic device (ASLD) has attracted increasing interests as one of the most promising post-CMOS device candidates, thanks to its low power, non-volatility and logic-in-memory structure. Here we investigate the key current-limiting factors and develop a physics-based model of ASLD through nano-magnet switching, t...
1506.03946v2
2019-01-15
Phenomenal magneto-elastoresistance of WTe$_{2}$: strain engineering of electronic and quantum transport properties
Elastoresistance describes the relative change of a material's resistance when strained. It has two major contributions: strain induced geometric and electronic changes. If the geometric factor dominates, like in ordinary metals such as copper, the elastoresistance is positive and rather small, i.e. typically of order ...
1901.05090v1
2019-10-26
Magic continuum in twisted bilayer WSe2
Emergent quantum phases driven by electronic interactions can manifest in materials with narrowly dispersing, i.e. "flat", energy bands. Recently, flat bands have been realized in a variety of graphene-based heterostructures using the tuning parameters of twist angle, layer stacking and pressure, and resulting in corre...
1910.12147v1
2020-06-26
YBCO-based non-volatile ReRAM tested in Low Earth Orbit
An YBCO-based test structure corresponding to the family of ReRAM devices associated with the valence change mechanism is presented. We have characterized its electrical response previous to its lift-off to a Low Earth Orbit (LEO) using standard electronics and also with the dedicated LabOSat-01 controller. Similar res...
2006.15062v1
2020-07-22
Machine Learning Potential for Hexagonal Boron Nitride Applied to Thermally and Mechanically Induced Rippling
We introduce an interatomic potential for hexagonal boron nitride (hBN) based on the Gaussian approximation potential (GAP) machine learning methodology. The potential is based on a training set of configurations collected from density functional theory (DFT) simulations and is capable of treating bulk and multilayer h...
2007.11448v3
2020-07-24
Determination of the spin Hall angle, spin mixing conductance and spin diffusion length in Ir/CoFeB for spin-orbitronic devices
Iridium is a very promising material for spintronic applications due to its interesting magnetic properties such as large RKKY exchange coupling as well as its large spin-orbit coupling value. Ir is for instance used as a spacer layer for perpendicular synthetic antiferromagnetic or ferrimagnet systems. However, only a...
2007.12413v1
2020-10-06
Conductance Model for Single-Crystalline/Compact Metal Oxide Gas Sensing Layers in the Non-Degenerate Limit: Example of Epitaxial SnO$_2$(101)
Semiconducting metal oxide (SMOX)-based gas sensors are indispensable for safety and health applications, e.g. explosive, toxic gas alarms, controls for intake into car cabins and monitor for industrial processes. In the past, the sensor community has been studying polycrystalline materials as sensors where the porous ...
2010.02962v1
2020-11-16
Ferroelectric tunnel junctions
My research is dedicated to the electronic properties of functional oxides. My activity specifically focuses on ferroelectric tunnel junctions in which an ultrathin layer of ferroelectric material is intercalated between two metallic electrodes. In these devices, polarization reversal induces large modifications of the...
2011.07864v1
2021-02-09
Quasi-quantized Hall response in bulk InAs
The quasi-quantized Hall effect (QQHE) is the three-dimensional (3D) counterpart of the integer quantum Hall effect (QHE),exhibited only by two-dimensional (2D) electron systems. It has recently been observed in layered materials, consisting of stacks of weakly coupled 2D platelets that are yet characterized by a 3D an...
2102.04928v3