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2018-12-18
An application of extensions of the Ramo-Shockley theorem to signals in silicon sensors
We discuss an extension of the Ramo-Shockley theorem that allows the calculation of signals in detectors that contain non-linear materials of arbitrary permittivity and finite conductivity (volume resistivity) as well as a static space-charge. The readout-electrodes can be connected by an arbitrary impedance network. T...
1812.07570v2
2018-12-19
Blue (In,Ga)N Light-Emitting Diodes with Buried n+-p+ Tunnel Junctions by Plasma-Assisted Molecular Beam Epitaxy
Blue light-emitting diodes (LEDs) consisting of a buried n+-p+ GaN tunnel junction, (In,Ga)N multiple quantum wells (MQWs) and a n+-GaN top layer are grown on single-crystal Ga-polar n+-GaN bulk wafers by plasma-assisted molecular beam epitaxy. The (In,Ga)N MQW active regions overgrown on the p+-GaN show chemically abr...
1812.07708v1
2019-01-07
Growth and Characterization of Fe0.95Se0.6Te0.4 Single Crystal
In this paper we present the single crystal growth of Fe0.95Se0.6Te0.4 high TC superconducting sample by the modified Bridgman technique. The x-ray diffraction pattern shows the single crystal nature of the sample, as only (00l) peaks are detectable. The stoichiometric composition has been verified by energy dispersive...
1901.01955v1
2019-11-06
Low frequency imaginary impedance at the superconducting transition of 2H-NbSe$_2$
The superconducting transition leads to a sharp resistance drop in a temperature interval that can be a small fraction of the critical temperature T$_c$. A superconductor exactly at T$_c$ is thus very sensitive to all kinds of thermal perturbations, including the heat dissipated by the measurement current. We show that...
1911.02340v2
2020-01-15
Enhanced Carrier Transport by Transition Metal Doping in WS2 Field Effect Transistors
High contact resistance is one of the primary concerns for electronic device applications of two-dimensional (2D) layered semiconductors. Here, we explore the enhanced carrier transport through metal-semiconductor interfaces in WS2 field effect transistors (FETs) by introducing a typical transition metal, Cu, with two ...
2001.05105v1
2020-01-20
Electrical conduction mechanisms of metal / high-Tc superconductor (YBCO) interfaces
Current-voltage characteristics of Au~/~YBa$_2$Cu$_3$O$_{7-\delta}$ interfaces (Au/YBCO), built on optimally-doped YBCO thin films, grown by pulsed laser deposition, were measured as a function of temperature in the 50 K to 270 K range, for two different resistance states. A non-trivial equivalent circuit model is prop...
2001.07237v1
2020-06-09
Fluctuations superconductivity and giant negative magnetoresistance in a gate voltage tuned 2D electron liquid with strong spin-orbit impurity scattering
We present a quantitative theory of the gate-voltage tuned superconductor-to-insulator transition (SIT) observed experimentally in the 2D electron liquid created in the (111) interface between crystalline SrTiO_3 and LaAlO_3 . Considering two fundamental opposing effects of Cooper-pair fluctuations; the critical conduc...
2006.05098v3
2020-08-15
Ultrahigh Doping of Graphene Using Flame-Deposited MoO3
The expected high performance of graphene-based electronics is often hindered by lack of adequate doping, which causes low carrier density and large sheet resistance. Many reported graphene doping schemes also suffer from instability or incompatibility with existing semiconductor processing. Here we report ultrahigh an...
2008.06794v1
2020-11-13
Large anomalous Hall angle in a topological semimetal candidate TbPtBi
The magnetotransport properties in antiferromagnetic half-Heusler single crystals of TbPtBi, a magnetic-field-induced topological semimetal with simple band structure, are investigated. We found that a nonmonotonic magnetic field dependence of the anomalous Hall resistivity in a high magnetic field (B>7T), which come f...
2011.06864v1
2021-03-09
Anisotropy of the In-Plane and Out-of-Plane Resistivity and the Hall Effect in the Normal State of Vicinal-Grown YBa$_{2}$Cu$_{3}$O$_{7-δ}$ Thin Films
The resistivity and the Hall effect in the copper-oxide high-temperature superconductor YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ (YBCO) are remarkably anisotropic. Using a thin film of YBCO grown on an off-axis cut SrTiO$_3$ substrate allows one to investigate these anisotropic transport properties in a planar and well-defined ...
2103.05511v1
2021-06-24
Erasable superconductivity in topological insulator Bi2Se3 induced by voltage pulse
Three-dimensional topological insulators (TIs) attract much attention due to its topologically protected Dirac surface states. Doping into TIs or their proximity with normal superconductors can promote the realization of topological superconductivity(SC) and Majorana fermions with potential applications in quantum comp...
2106.13207v1
2021-06-29
Low Resistance III-V Hetero-contacts to N-Ge
We experimentally study III-V/Ge heterostructure and demonstrate InGaAs hetero-contacts to n-Ge with a wide range of In % and achieve low contact resistivity ($\rho_C$) of $5\times10^{-8} \Omega\cdot cm^2$ for Ge doping of $3 \times 10^{19} cm^{-3}$. This results from re-directing the charge neutrality level (CNL) near...
2106.15099v1
2021-09-08
Unusual Magnetic Properties in Layered Magnetic Topological Insulator EuSn2As2
EuSn2As2 with layered rhombohedral crystal structure is proposed to be a candidate of intrinsic antiferromagnetic (AFM) topological insulator. Here, we have investigated systematic magnetoresistance (MR) and magnetization measurements on the high quality EuSn2As2 single crystal with the magnetic field both parallel and...
2109.03414v1
2022-05-12
Shubnikov-de Haas and de Haas-van Alphen oscillation in Czochralski grown CoSi single crystal
Anisotropic transport, Shubnikov-de Haas (SdH), and de Haas-van Alphen (dHvA) quantum oscillations studies are reported on a high-quality CoSi single crystal grown by the Czochralski method. Temperature-dependent resistivities indicate the dominating electron-electron scattering. Magnetoresistance (MR) at 2 K reaches 6...
2205.05881v1
2022-07-05
Anderson localization crossover in 2D Si systems: The past and the present
Using Ioffe-Regel-Mott (IRM) criterion for strong localization crossover in disordered doped 2D electron systems, we theoretically study the relationships among the three key experimentally determined localization quantities: critical density ($n_\mathrm{c}$), critical resistance ($\rho_\mathrm{c}$), and sample quality...
2207.02220v1
2022-08-22
Electronic structure and physical properties of EuAuAs single crystal
High-quality single crystals of EuAuAs were studied by means of powder x-ray diffraction, magnetization, magnetic susceptibility, heat capacity, electrical resistivity and magnetoresistance measurements. The compound crystallizes with a hexagonal structure of the ZrSiBe type (space group $P6_3/mmc$). It orders antiferr...
2208.10405v1
2022-09-18
Superparamagnetic and metal-like Ru2TiGe: a propitious thermoelectric material
We report a study of structural, magnetic, heat capacity and thermoelectric properties of a Rubased Heusler alloy, Ru2TiGe. The magnetic measurements reveal that at higher temperatures, diamagnetic and Pauli paramagnetic contributions dominate the magnetic behaviour whereas, at lower temperatures (T<= 20 K), superparam...
2209.08474v1
2022-11-02
Umklapp electron-electron scattering in bilayer graphene moiré superlattice
Recent experimental advances have been marked by the observations of ballistic electron transport in moir\'e superlattices in highly aligned heterostructures of graphene and hexagonal boron nitride (hBN). Here, we predict that a high-quality graphene bilayer aligned with an hBN substrate features $T^2$-dependent resist...
2211.01005v1
2023-01-11
Application of the partial Dirichlet-Neumann contact algorithm to simulate low-velocity impact events on composite structures
Impact simulations for damage resistance analysis are computationally intensive due to contact algorithms and advanced damage models. Both methods, which are the main ingredients in an impact event, require refined meshes at the contact zone to obtain accurate predictions of the contact force and damage onset and propa...
2301.05552v2
2023-01-19
Unusual anisotropic magnetoresistance due to magnetization-dependent spin-orbit interactions
One of recent surprising discoveries is the unusual anisotropic magnetoresistance (UAMR) that depends on two magnetization components perpendicular to the current differently, in contrast to the conventional anisotropic magnetoresistance (AMR) that predicts no change in resistance when the magnetization varies in the p...
2301.07886v1
2023-03-06
Timing resistive plate chambers for thermal neutron detection with 3D position sensitivity
An optimized design of a neutron detector based on timing RPCs (Resistive Plate Chambers) with boron-10 neutron converters is presented. The detector is composed of a stack of ten double gap RPCs with aluminium cathode plates coated on both sides with $^{10}B_{4}C$. This design enables simultaneous determination with h...
2303.03461v1
2023-03-22
Effect of gamma radiation on electrical properties of diffusive memristor devices
Diffusive memristors continue to receive tremendous interest due to their ability to emulate biological neurons and thus aid the development of bio-inspired computation technology. A major issue with the diffusive memristor is the inability to reliably control the formation of the conduction filaments which affects bot...
2303.12762v1
2023-07-18
Universal scaling near band-tuned metal-insulator phase transitions
We present a theory for band-tuned metal-insulator transitions based on the Kubo formalism. Such a transition exhibits scaling of the resistivity curves, in the regime where $T\tau >1$ or $\mu \tau>1$, where $\tau$ is the scattering time and $\mu$ the chemical potential. At the critical value of the chemical potential,...
2307.09292v1
2023-10-10
The black hole to black hole phase transition probed by the D3-D7 model fermionic spectral functions
We consider the D3-D7 model and analyze the phase transition from the black-hole phase to another black-hole phase using the spectral function of a probe fermion on D7 in the presence of the finite density and temperature. From the fermionic spectral functions, we study the temperature dependence of the decay rate and ...
2310.06317v1
2023-10-22
Electrical conductivity enhancement of epitaxially grown TiN thin films
Titanium nitride (TiN) presents superior electrical conductivity with mechanical and chemical stability and compatibility with the semiconductor fabrication process. Here, we fabricated epitaxial and polycrystalline TiN (111) thin films on MgO (111), sapphire (001), and mica substrates at 640oC and room temperature by ...
2310.14208v1
2023-11-20
Magnetic-field-induced nonlinear transport in HfTe5
The interplay of electron correlations and topological phases gives rise to various exotic phenomena including fractionalization, excitonic instability, and axionic excitation. Recently-discovered transition-metal pentatellurides can reach the ultra-quantum limit in low magnetic fields and serve as good candidates for ...
2311.11517v1
2023-11-29
Lateral NbS$_2$/MoS$_2$/NbS$_2$ transistors: physical modeling and performance assessment
Reducing the contact resistance of field-effect transistors based on two-dimensional materials is one of the key improvements required to to enable the integration of such transistors in an industrially relevant process. Suitably designed lateral heterojunctions provide an opportunity to independently tailor the contac...
2311.18031v1
2024-02-23
Electrical Scanning Probe Microscope Measurements Reveal Surprisingly High Dark Conductivity in Y6 and PM6:Y6 and Non-Langevin Recombination in PM6:Y6
We used broadband local dielectric spectroscopy (BLDS), an electric force microscopy technique, to make non-contact measurements of conductivity in the dark and under illumination of PM6:Y6 and Y6 prepared on ITO and PEDOT:PSS/ITO. Over a range of illumination intensities, BLDS spectra were acquired and fit to an imped...
2402.15501v1
2021-05-07
Integrating van der Waals materials on paper substrates for electrical and optical applications
Paper holds the promise to replace silicon substrates in applications like internet of things or disposable electronics that require ultra-low-cost electronic components and an environmentally friendly electronic waste management. In the last years, spurred by the abovementioned properties of paper as a substrate and t...
2105.03486v1
2017-06-29
Origin of Contact Resistance at Ferromagnetic Metal-Graphene Interfaces
Edge contact geometries are thought to yield ultralow contact resistances in most non-ferromagnetic metal-graphene interfaces owing to their large metal-graphene coupling strengths. Here, we examine the contact resistance of edge- versus surface-contacted ferromagnetic metal-graphene interfaces (i.e. nickel- and cobalt...
1706.09591v1
2023-09-22
Non-equilibrium Thermal Resistance of Interfaces Between III-V Compounds
Interfacial thermal resistance has been often estimated and understood using the Landauer formalism that assumes incident phonons with equilibrium distribution. However, previous studies suggest that phonons are out-of-equilibrium near the interface because of the heat flow through the leads and the scattering of phono...
2309.13187v1
2003-10-28
On magnetic field generation in Kolmogorov turbulence
We analyze the initial, kinematic stage of magnetic field evolution in an isotropic and homogeneous turbulent conducting fluid with a rough velocity field, v(l) ~ l^alpha, alpha<1. We propose that in the limit of small magnetic Prandtl number, i.e. when ohmic resistivity is much larger than viscosity, the smaller the r...
0310780v2
1999-08-04
Polarization fields in nitride nanostructures: ten points to think about
Macroscopic polarization, both of intrinsic and piezoelectric nature, is unusually strong in III-V nitrides, and the built in electric fields in the layers of nitride-based nanostructures, stemming from polarization changes at heterointerfaces, have a major impact on the properties of single and multiple quantum wells,...
9908060v1
2001-02-06
Observation of superconductivity in Y$_2$PdGe$_3$, structurally same as MgB$_2$
The results of electrical resistance (1.4 - 300 K), magnetization (2-300 K) and heat-capacity (2 - 50 K) measurements in Y$_2$PdGe$_3$, found to crystallize in a AlB$_2$-derived hexagonalstructure, are reported. The results establish that this compound is superconducting below 3 K. This obervation is interesting consid...
0102110v1
2002-05-08
Complex Quantum Phenomena in a Bilayered Calcium Ruthenate
Ca$_3$Ru$_2$O$_7$ undergoes an antiferromagnetic transition at $T_{\text{N}}=56 $K, followed by a Mott-like (MI) transition at $T_{\text{MI}}=48$ K. This nonmetallic ground state, with a charge gap of 0.1 eV, is suppressed by a highly anisotropic metamagnetic transition that leads to a fully spin-polarized metallic sta...
0205151v1
2002-06-10
Realization of La2MnVO6: Search for half-metallic antiferromagnetism?
Single-phase polycrystalline La2MnVO6 samples were synthesized by arc melting and characterized by X-ray diffraction, magnetization and resistivity measurements. We find that the compound has cubic (space group), partly ordered double perovskite structure. The sample exhibits ferrimagnetic behavior and variable-range h...
0206146v1
2002-07-09
Perspectives of superconducting MgB2 for microwave applications
We discuss the temperature, frequency, and power-dependent surface resistance of the boride superconductor MgB2 in relation to possible applications for passive microwave devices. The data available in the literature are compared with results for polycrystalline Nb3Sn and epitaxial YBa2Cu3O7-x, which are representative...
0207226v1
2002-08-15
Superconductivity in Ba_2Sn_3Sb_6 and SrSn_3Sb_4
Resistivity and ac magnetic susceptibility measurements on Ba2Sn3Sb6 and SrSn3Sb4 indicate that these Zintl compounds display a transition to a superconducting phase at Tc = 3.9 K. The Meissner effect was observed for Ba2Sn3Sb6 under an applied field of 25 Oe. The signatures for superconductivity, such as high and low ...
0208313v1
2002-11-22
Correlations and Semimetallic Behaviors in Pyrochlore Oxide Cd2Re2O7
Electronic properties of the metallic pyrochlore oxide Cd2Re2O7 are studied by means of electrical resistivity and Hall measurements. Semimetallic band structures are revealed as expected from band structure calculations. It is found that large changes in carrier density and mass occur at the structural phase transitio...
0211517v1
2004-02-02
Dielectric responses of the layered cobalt oxysulfide Sr_2Cu_2CoO_2S_2 with CoO_2 square-planes
We have studied the dielectric responses of the layered cobalt oxysulfide Sr$_2$Cu$_2$CoO$_2$S$_2$ with the CoO$_2$ square-planes. With decreasing temperature below the N\'eel temperature, the resistivity increases like a semiconductor, and the thermopower decreases like a metal. The dielectric constant is highly depen...
0402034v1
2005-01-28
Ce doping in T-La2CuO4 films: Broken electron-hole symmetry for high-Tc superconductivity
We attempted Ce doping in La2CuO4 with the K2NiF4 (T) structure by molecular beam epitaxy. At low growth temperature and with an appropriate substrate choice, we found that Ce can be incorporated into the K2NiF4 lattice up to x ~ 0.06, which had not yet been realized in bulk synthesis. The doping of Ce makes T-La2-xCex...
0501703v1
2005-09-05
Large magnetoresistance and magnetocaloric effect above 70 K in Gd2Co2Al, Gd2Co2Ga and Gd7Rh3
The electrical resistivity, magnetization and heat-capacity behavior of the Gd-based compounds, Gd2Co2Al, Gd2Co2Ga and Gd7Rh3, ordering magnetically at TC= 78 K, TC= 76 K and TN= 140 K have been investigated as a function of temperature and magnetic field. All these compounds are found to show large magnetoresistance (...
0509107v1
2006-10-11
Intergrain connectivity and resistive broadening in vortex state: a comparison between MgB2, NbSe2 and Bi2Sr2Ca2Cu3O10 superconductors
Magnetoresistance and radio frequency penetration depth techniques are used to study grain connectivity and broadening of superconducting transition. We study and compare these issues in clean polycrytalline samples of three different superconducting systems e.g. MgB2, NbSe2 and Bi2Sr2Ca2Cu3O10. From the rf response, t...
0610295v1
2007-03-25
Novel dynamical effects and glassy response in strongly correlated electronic system
We find an unconventional nucleation of low temperature paramagnetic metal (PMM) phase with monoclinic structure from the matrix of high-temperature antiferromagnetic insulator (AFI) phase with tetragonal structure in strongly correlated electronic system $BaCo_{0.9}Ni_{0.1}S_{1.97}$. Such unconventional nucleation lea...
0703647v1
2007-07-05
Anomalous exchange coupling in transition-metal-oxide based superlattices with antiferromagnetic spacer layers
A direct correlation is seen between the coercive field (HC) and the magnetic-field-dependent resistivity (MR) in SrMnO3/SrRuO3 superlattices of perpendicular magnetic anisotropy. The magnetoresistance shows a sharp jump at Hc for in-plane current and the out-of-plane magnetic field. Both HC and high-field MR also osci...
0707.0768v1
2007-08-10
Coherent quasiparticle transport in grain boundary junctions employing high-Tc superconductors
Magneto-fluctuations of the normal resistance RN have been reproducibly observed in YBa2Cu3O7-d biepitaxial grain boundary junctions at low temperatures. We attribute them to mesoscopic transport in narrow channels across the grain boundary line, occurring in an unusual energy regime. The Thouless energy appears to be ...
0708.1448v1
2007-09-26
Single crystal growth and anisotropy of CeRuPO
We report on the single crystal growth of the ferromagnetic Kondo lattice system CeRuPO using a Sn flux method. Magnetic susceptibility and electrical resistivity measurements indicate strong anisotropy of this structurally layered compound. They evidence that the magnetic moments order ferromagnetically along the c-di...
0709.4144v2
2007-11-30
Large voltage from spin pumping in magnetic tunnel junctions
We studied the response of a ferromagnet-insulator-normal metal tunnel structure under an external oscillating radio frequency (R.F.) magnetic field. The D. C. voltage across the junction is calculated and is found not to decrease despite the high resistance of the junction; instead, it is of the order of $\mu V$ to $1...
0711.4939v1
2008-01-07
High Performance Thermal Interface Technology Overview
An overview on recent developments in thermal interfaces is given with a focus on a novel thermal interface technology that allows the formation of 2-3 times thinner bondlines with strongly improved thermal properties at lower assembly pressures. This is achieved using nested hierarchical surface channels to control th...
0801.1046v1
2008-01-17
Stability of RVB hole stripes in high-temperature superconductors
Indications of density-wave states in underdoped cuprates, coming from recent STM (scanning tunneling microscopy) and Hall-resistance measurements, have raised new concerns whether stripes could be stabilized in the superconducting phase of cuprate materials, even in the absence of antiferromagnetism. Here, we investig...
0801.2722v2
2008-08-03
Superconductivity in Yttrium Iron Oxyarsenide System
Iron-based oxypnictides substituted with yttrium have been prepared via a conventional solid state reaction. The product after first 50 hours of reaction showed diamagnetic-like transition at around 10 K but was not superconducting, while additional 72 hours of high temperature heat treatment was required to yield supe...
0808.0288v2
2008-09-16
Interface heat transfer between crossing carbon nanotubes, and the thermal conductivity of nanotube pellets
We theoretically compute the interface thermal resistance between crossing single walled carbon nanotubes of various chiralities, using an atomistic Green's function approach with semi-empirical potentials. The results are then used to model the thermal conductivity of three dimensional nanotube pellets in vacuum. For ...
0809.2660v1
2008-10-29
High-Mobility Few-Layer Graphene Field Effect Transistors Fabricated on Epitaxial Ferroelectric Gate Oxides (Supplementary Information)
Supplementary Information to arXiv:0810.4466: 1. Characterizations of Pb(Zr_0.2Ti_0.8)O_3 (PZT) films. 2. Substrate preparation before the exfoliation of graphene. 3. The band structure of FLG. 4. Dielectric constant measurements of PZT. 5. rho(V_g) and R_H(V_g) fitting inside the band overlap regime. 6. The deformatio...
0810.5339v1
2008-12-20
Mobility Extraction and Quantum Capacitance Impact in High Performance Graphene Field-effect Transistor Devices
The field-effect mobility of graphene devices is discussed. We argue that the graphene ballistic mean free path can only be extracted by taking into account both, the electrical characteristics and the channel length dependent mobility. In doing so we find a ballistic mean free path of 300nm at room-temperature for a c...
0812.3927v1
2009-01-07
Electrically Controlled Magnetic Memory and Programmable Logic based on Graphene/Ferromagnet Hybrid Structures
It has been shown that the combining of the electrical effect on the exchange bias field with giant magneto-resistance effect of the graphene/ferromagnet hybrid structures reveals a new non-volatile magnetic random access memory device conception. In such device an electric bias realizes the writing bits instead a magn...
0901.0926v1
2009-03-21
Graphite in the bi-layer regime: in-plane transport
An interplay between the increase in the number of carriers and the decrease in the scattering time is expected to result in a saturation of the in-plane resistivity, $\rho_{ab}$, in graphite above room temperature. Contrary to this expectation, we observe a pronounced increase in $\rho_{ab}$ in the interval between 30...
0903.3646v2
2009-04-22
Emergence of dissipative structures in current-carrying superconducting wires
We discuss the emergence of a spontaneous temperature and critical current spatial modulation in current-carrying high temperature superconducting wire. The modulation of the critical current along the wire on a scale of 3 - 10 mm forces a fraction of the transport current to crisscross the resistive interface between ...
0904.3474v1
2009-04-23
Crystal growth, structure and ferromagnetic properties of a Ce3Pt23Si11 single crystal
A high-quality single crystal of Ce3Pt23Si11 has been grown using the Czochralski method. The crystal structure is presented and the chemical composition has been checked using an electron microprobe analyzer. Measurements of the electrical resistivity and magnetic susceptibility performed at low temperature show a fer...
0904.3720v1
2009-05-29
Growth of Sr1-xCaxRuO3 thin films by metalorganic aerosol deposition
We report the growth of thin films of Sr1-xCaxRuO3 on SrTiO3 and MgO substrates by metalorganic aerosol deposition. The structure and microstructure is characterized by X-ray diffraction and room-temperature scanning tunnelling microscopy (STM), respectively. STM indicates in-plane epitaxy and a small surface roughness...
0905.4896v2
2009-09-07
Anomalous magnetotransport and cyclotron resonance of high mobility magnetic 2DHGs in the quantum Hall regime
Low temperature magnetotransport measurements and far infrared transmission spectroscopy are reported in molecular beam epitaxial grown two-dimensional hole systems confined in strained InAs quantum wells with magnetic impurities in the channel. The interactions of the free holes spin with the magnetic moment of 5/2 pr...
0909.1124v1
2010-08-15
Unconventional Anomalous Hall Effect in the Metallic Triangular-Lattice Magnet PdCrO2
We experimentally reveal an unconventional anomalous Hall effect (UAHE) in a quasi-two-dimensional triangular-lattice antiferromagnet PdCrO2. Using high quality single crystals of PdCrO2, we found that the Hall resistivity deviates from the conventional behavior below T* = 20 K, noticeably lower than TN = 37.5 K, at wh...
1008.2503v1
2010-08-27
Metal-nonmetal transition in LixCoO2 thin film and thermopower enhancement at high Li concentration
We investigate the transport properties of LixCoO2 thin films whose resistivities are nearly an order of magnitude lower than those of the bulk polycrystals. A metal-nonmetal transition occurs at ~0.8 in a biphasic domain, and the Seebeck coefficient (S) is drastically increased at ~140 K (= T*) with increasing the Li ...
1008.4635v1
2010-10-21
Atomistic quantum transport modeling of metal-graphene nanoribbon heterojunctions
We calculate quantum transport for metal-graphene nanoribbon heterojunctions within the atomistic self-consistent Schr\"odinger/Poisson scheme. Attention is paid on both the chemical aspects of the interface bonding as well the one-dimensional electrostatics along the ribbon length. Band-bending and doping effects stro...
1010.4393v1
2010-11-02
Spin connection and boundary states in a topological insulator
We study the surface resistivity of a three-dimensional topological insulator when the boundaries exhibit a non trivial curvature. We obtain an analytical solution for a spherical topological insulator, and we show that a non trivial quantum spin connection emerges from the three dimensional band structure. We analyze ...
1011.0565v1
2010-11-20
Imaging Dissipation and Hot Spots in Carbon Nanotube Network Transistors
We use infrared thermometry of carbon nanotube network (CNN) transistors and find the formation of distinct hot spots during operation. However, the average CNN temperature at breakdown is significantly lower than expected from the breakdown of individual nanotubes, suggesting extremely high regions of power dissipatio...
1011.4551v2
2011-05-16
Coulomb drag in graphene
We calculate theoretically the Coulomb drag resistivity for two graphene monolayers spatially separated by a distance "$d$". We show that the frictional drag induced by inter-layer electron-electron interaction goes asymptotically as $T^2/n^3$ and $T^2 \ln(n)/n$ in the high-density ($k_F d \gg 1$) and low-density ($k_F...
1105.3203v2
2011-07-23
Modified exponential I(U) dependence and optical efficiency of AlGaAs SCH lasers in computer modeling with Synopsys TCAD
Optical and electrical characteristics of AlGaAs lasers with separate confinement heterostructures are modeled by using Synopsys's Sentaurus TCAD, and open source software. We propose a modified exponential $I-V$ dependence to describe electrical properties. A simple analytical, phenomenological model is found to descr...
1107.4668v1
2011-08-20
Demonstration of Forward Inter-band Tunneling in GaN by Polarization Engineering
We report on the design, fabrication, and characterization of GaN interband tunnel junction showing forward tunneling characteristics. We have achieved very high forward tunneling currents (153 mA/cm2 at 10 mV, and 17.7 A/cm2 peak current) in polarization-engineered GaN/InGaN/GaN heterojunction diodes grown by plasma a...
1108.4075v1
2012-04-10
Tunneling conduction in graphene/(poly)vinyl alcohol composites
Graphene/(Poly)vinyl alcohol (PVA) composite film with thickness $60 \mu m$ were synthesized by solidification of a PVA solution comprising of dispersed graphene nanosheets. The close proximity of the graphene sheets enables the fluctuation induced tunneling of electrons to occur from one sheet to another. The dielectr...
1204.2126v2
2012-07-27
Theoretical model of structure-dependent conductance crossover in disordered carbon
We analyze the effects of sp^2/sp^3 bond-aspect ratio on the transport properties of amorphous carbon quasi-1D structures where structural disorder varies in a very non-linear manner with the effective bandgap. Using a tight-binding approach the calculated electron transmission showed a high probability over a wide reg...
1207.6478v1
2012-11-22
Physical properties and band structure of reactive molecular beam epitaxy grown oxygen engineered HfO$_{2\pm x}$
We have conducted a detailed thin film growth structure of oxygen engineered monoclinic HfO$_{2\pm x}$ grown by reactive molecular beam epitaxy (MBE). The oxidation conditions induce a switching between ($\bar{1}11$) and (002) texture of hafnium oxide. The band gap of oxygen deficient hafnia decreases with increasing a...
1211.5215v1
2013-05-21
High sensitive quasi freestanding epitaxial graphene gassensor on 6H-SiC
We have measured the electrical response to NO$_2$, N$_2$, NH$_3$ and CO for epitaxial graphene and quasi freestanding epitaxial graphene on 6H-SiC substrates. Quasi freestanding epitaxial graphene shows a 6 fold increase in NO2 sensitivity compared to epitaxial graphene. Both samples show a sensitivity better than the...
1305.4737v1
2013-09-04
Enhancing high-temperature thermoelectric properties of PtAs2 by Rh doping
The effects of Rh doping on the thermoelectric properties of Pt1-xRhxAs2 (x = 0, 0.005, and 0.01) with pyrite structure were studied by conducting measurements of electrical resistivity rho, Seebeck coefficient S, and thermal conductivity kappa. The sample with x = 0.005 exhibited large S and low rho, resulting in a ma...
1309.0939v1
2013-10-06
Charge transport through graphene junctions with wetting metal leads
Graphene is believed to be an excellent candidate material for next-generation electronic devices. However, one needs to take into account the nontrivial effect of metal contacts in order to precisely control the charge injection and extraction processes. We have performed transport calculations for graphene junctions ...
1310.1640v1
2013-11-17
Giant magnetothermopower in charge ordered Nd0.75Na0.25MnO3
We report magnetization, resistivity and thermopower in the charge-orbital ordered antiferromagnet Nd0.75Na0.25MnO3. Magnetic-field induced collapse of antiferromagnetism is found to be accompanied by a giant negative magnetothermopower (= 80-100% for a field change of 5T) over a wide temperature (T = 60-225K) and gian...
1311.4165v1
2014-02-05
Selective molecular capture mechanism in carbon nanotube networks
Recent air pollution issues have raised significant attention to develop efficient air filters, and one of the most promising candidates is that enabled by nanofibers. We explore here selective molecular capture mechanism for volatile organic compounds in carbon nanotube networks by performing atomistic simulations. Th...
1402.1011v1
2016-01-06
Effect of SW defect on structural and transport properties of silicene nanoribbons
Using density functional theory and non-equilibrium Greens function technique, we performed theoretical investigations on the structural and transport properties of zigzag silicene nanoribbons with Stone-Wales defect. The calculated formation energy is significantly lower than that of graphene and silicene, which impli...
1601.01053v1
2016-01-30
Slippery but tough - the rapid fracture of lubricated frictional interfaces
We study the onset of friction for rough contacting blocks whose interface is coated with a thin lubrication layer. High speed measurements of the real contact area and stress fields near the interface reveal that propagating shear cracks mediate lubricated frictional motion. While lubricants reduce interface resistanc...
1602.00085v2
2016-10-09
Physical properties of KMgBi single crystals
KMgBi single crystals are grown by using the Bi flux successfully. KMgBi shows semiconducting behavior with a metal-semiconductor transition at high temperature region and a resistivity plateau at low temperature region, suggesting KMgBi could be a topological insulator with a very small band gap. Moreover, KMgBi exhib...
1610.02699v2
2017-06-27
Influence of Heat Treatment on the Corrosion Behavior of Purified Magnesium and AZ31 Alloy
Magnesium and its alloys are ideal for biodegradable implants due to their biocompatibility and their low-stress shielding. However, they can corrode too rapidly in the biological environment. The objective of this research was to develop heat treatments to slow the corrosion of high purified magnesium and AZ31 alloy i...
1706.08663v1
2017-12-06
Superconductivity in the ternary compound SrPt$_{10}$P$_4$ with complex new structure
We report superconductivity at 1.4K in the ternary SrPt$_{10}$P$_4$ with a complex new structure. SrPt$_{10}$P$_4$ crystallizes in a monoclinic space-group C2/c (\#15) with lattice parameters a= 22.9151(9)$\AA$, b= 13.1664(5)$\AA$, c=13.4131(5)$\AA$, and $\beta$= 90.0270(5)${^\circ}$. Bulk superconductivity in the samp...
1712.02010v1
2018-03-06
Comparative study on magnetoresistance of carbon-cobalt nanocomposite thin films grown by pulsed laser deposition
We present a comparative study on the influence of applied magnetic field on the resistance of $C_{1-x}Co_x$ thin films (with $x=0.1$, $0.15$ and $0.2$) grown on $Si$ substrate by pulsed laser deposition technique. It is found that the behavior of magnetoresistance (MR) drastically depends on the temperature. Namely, a...
1803.02064v1
2018-04-27
Emergent antiferromagnetism of YTiO3 in YTiO3-CaTiO3 superlattices
Transport and magnetoresistance measurements are performed on metallic, high-carrier density YTiO3-CaTiO3 superlattices as a probe towards the investigation of an emergent magnetic order of YTiO3. On varying the thickness of YTiO3 while keeping the CaTiO3 layer thickness constant in the superlattices, a low-temperature...
1804.10333v1
2018-10-01
Poly(ionic liquid)-Derived Carbon with Site-Specific N-Doping and Biphasic Heterojunction for Enhanced CO2 Capture and Sensing
CO2 capture is a pressing global environmental issue that drives scientists to develop creative strategies for tackling this challenge. The concept in this contribution is to produce site specific nitrogen doping in microporous carbon fibers. It creates a carbon/carbon heterojunction by using poly(ionic liquid) (PIL) a...
1810.06418v1
2020-09-13
Adiabatic theory of SET and RESET transitions
We develop a phenomenological theory of pulse induced phase transformations behind the SET (from high to low resistive state) and RESET (backward) processes in nonvolatile memory. We show that in modern era devices, both evolve in the adiabatic regime with energy deposition time much shorter than that of thermalization...
2009.06057v2
2007-10-29
Thermoelectrical manipulation of nano-magnets
We propose a device that can operate as a magneto-resistive switch or oscillator. The device is based on a spin-thermo-electronic control of the exchange coupling of two strong ferromagnets through a weakly ferromagnetic spacer. We show that the local Joule heating due to a high concentration of current in a magnetic p...
0710.5477v1
2007-10-30
Devitrification of a glass-like arrested ferromagnetic phase in La0.5Ca0.5MnO3
Magnetization measurements in La0.5Ca0.5MnO3 manganite show that the high-temperature long-range ferromagnetic-metallic phase transforms to antiferromagnetic-insulating phase, although a fraction of ferromagnetic-metallic phase undergoes glass-like kinetic arrest and coexists at low temperature with the equilibrium ant...
0710.5585v1
2019-03-26
Patterning of diamond with 10 nm resolution by electron-beam-induced etching
We report on mask-less, high resolution etching of diamond surfaces, featuring sizes down to 10 nm. We use a scanning electron microscope (SEM) together with water vapor, which was injected by a needle directly onto the sample surface. Using this versatile and low-damage technique, trenches with different depths were e...
1903.10824v1
2015-07-11
Insulator/metal phase transition and colossal magnetoresistance in holographic model
Within massive gravity, we construct a gravity dual for insulator/metal phase transition and colossal magnetoresistance (CMR) effect found in some manganese oxides materials. In heavy graviton limit, a remarkable magnetic-field-sensitive DC resistivity peak appears at the Curie temperature, where an insulator/metal pha...
1507.03105v2
2019-10-23
Percolation with plasticity for neuromorphic computing
We introduce the percolation with plasticity (PWP) systems that exhibit neuromorphic functionalities including multi-valued memory, random number generation, matrix-vector multiplication, and associative learning. PWP systems have multiple (N >> 1) interfaces with external circuitry (electrodes) allowing N! >> 1 measur...
1910.10535v1
2019-11-04
Closed-loop electric currents and non-local resistance measurements with wide F/I/N tunnel contacts
Lateral spin valves are used to generate and characterize pure spin currents. Non-local voltage measured in such structures provides information about spin polarization and spin decay rates. For wide high-transparency F/N contacts it was shown that the Johnson-Silsbee non-local effect is substantially enriched by close...
1911.01034v1
2020-01-08
Electrical and optical properties of hydrated amorphous vanadium oxide
Electrical and optical properties of amorphous vanadium oxide thin films obtained by electrochemical anodic oxidation are studied. It is shown that under cathodic polarization the hydrogen insertion into vanadium oxide from an electrolyte occurs. Metal-insulator transition in amorphous HxVO2 is found to be preserved up...
2001.02418v1
2020-01-08
Electrical conductivity of vanadium dioxide switching channel
The electrical conductivity of the switching channel of vanadium dioxide thin-film sandwich structures is studied over a wide temperature range (15-300 K). It is shown that the electrical resistance of the channel varies with temperature as R~exp(aT-b/T) in the high-temperature region (above 70 K). The experimental res...
2001.03053v1
2021-03-19
Side-leakage of facemask
Face masks are used to trap particles (or fluid drops) in a porous material (filter) in order to avoid or reduce the transfer of particles between the human lungs (or mouth and nose) and the external environment. The air exchange between the lungs and the environment is assumed to occur through the facemask filter. How...
2103.10970v1
2021-04-25
High Pressure RTSC-Hydrides are Extreme Hard Type-II Superconductors
It is argued that most of the RTSC hydrides are intrinsic hard type-II superconductors with strong pinning effects. The pinning centers are long columnar-like defects, with the radius of the order of the superconducting coherence length. The core and electromagnetic pinning are both equally operative, thus giving maxim...
2104.12214v1
2022-11-19
A Large-Area RPC Detector for Muography
A muon telescope equipped with four Resistive Plate Chambers of 2 m$^{2}$ per plane was tested with the muon scattering tomography technique. The telescope was operated during several hours with high atomic number materials located at its center with two detector planes on each side. With an intrinsic efficiency above ...
2211.10795v1
2023-05-22
Microcontroller Based AVR Hazardous Gas Detection System using IoT
MQ-6 Semiconductor Sensor for Combustible Gas detection is a Sensitive Gas sensor. The sensitive material of this MQ-6 gas sensor is SnO2, which works with lower conductivity in clean air. When the target combustible gas exist, the sensors conductivity is higher along with the gas concentration rising. As the conductiv...
2305.12855v1
2017-10-25
High-temperature cyclic oxidation kinetics and microstructural transition mechanisms of Ti-6Al-4V composites reinforced with hybrid (TiC+TiB) networks
The microstructural features and high-temperature oxidation resistance of hybrid (TiC+TiB) networks reinforced Ti-6Al-4V composites were investigated after fabricated with reaction hot pressing technique. The inhomogeneous distribution of hybrid reinforcers resulted in a sort of stress-induced grain refinement for {\al...
1710.09315v1
2007-07-20
A mechanism for unipolar resistance switching in oxide non-volatile memory devices
Building on a recently introduced model for non-volatile resistive switching, we propose a mechanism for unipolar resistance switching in metal-insulator-metal sandwich structures. The commutation from the high to low resistance state and back can be achieved with successive voltage sweeps of the same polarity. Electro...
0707.3077v1
2013-08-02
Precision Quantum Hall Resistance Measurement on Epitaxial Graphene Device in Low Magnetic Field
Precision quantum Hall resistance (QHR) measurements were performed on large-area epitaxial graphene device at low magnetic fields (B = 2 T - 8 T) at temperature T = 1.5 K. Hall resistance was measured using Cryogenic Current Comparator resistance bridge with high biasing current Isd = 40 micro ampere. The results show...
1308.0456v1