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2016-10-18
Light emission, light detection and strain sensing with nanocrystalline graphene
Graphene is of increasing interest for optoelectronic applications exploiting light detection, light emission and light modulation. Intrinsically light matter interaction in graphene is of a broadband type. However by integrating graphene into optical micro cavities also narrow band light emitters and detectors have be...
1610.05513v1
2017-02-01
Pore ordering in mesoporous matrices induced by different directing agents
Mesoporous silica particles of MCM-41 type were synthesized by sol-gel method from tetraethyl orthosilicate (TEOS) in 2-methoxyethanol and deionized water mixture in base conditions at room temperature. Ammonia or sodium hydroxides were used as catalysts and cetyl-trimethylammonium bromide (CTAB) and n-dodecyl-trimethy...
1702.00366v1
2017-10-27
Materials considerations for forming the topological insulator phase in InAs/GaSb heterostructures
In an ideal InAs/GaSb bilayer of appropriate dimension in-plane electron and hole bands overlap and hybridize, and a topologically non-trivial, or quantum spin Hall (QSH) insulator, phase is predicted to exist. The in-plane dispersion's potential landscape, however, is subject to microscopic perturbations originating f...
1710.10095v1
2014-08-05
Emergent surface superconductivity of nanosized Dirac puddles in a topological insulator
Surfaces of three-dimensional topological insulators have emerged as one of the most remarkable states of condensed quantum matter1-5 where exotic electronic phases of Dirac particles should arise1,6-8. Here we report a discovery of surface superconductivity in a topological material (Sb2Te3) with resistive transition ...
1408.1046v1
2019-07-31
Coexisting 1T/2H polymorphs, reentrant resistivity behavior, and charge distribution in MoS2-hBN 2D/2D composite thin films
In view of their immensely intriguing properties, two dimensional materials are being intensely researched in search of novel phenomena and diverse application interests, however, studies on the realization of nanocomposites in the application-worthy thin-film platform are rare. Here we have grown MoS2-hBN composite th...
1907.13522v1
2022-02-21
Towards fully two-dimensional spintronic devices
Within the field of spintronics major efforts are directed towards developing applications for spin-based transport devices made fully out of two-dimensional (2D) materials. In this work we present an experimental realization of a spin-valve device where the generation of the spin signal is exclusively attributed to th...
2202.09972v1
2016-03-10
Möbius Kondo Insulators
Heavy fermion materials have recently attracted attention for their potential to combine topological protection with strongly correlated electron physics. To date, the ideas of topological protection have been restricted to the heavy fermion or "Kondo" insulators with the simplest point-group symmetries. Here we argue ...
1603.03435v4
2017-07-14
Mesoscale simulations of confined Nafion thin films
The morphology and transport properties of thin films of the ionomer Nafion, with thicknesses on the order of the bulk cluster size, have been investigated as a model system to explain the anomalous behaviour of catalyst/electrode-polymer interfaces in membrane-electrode assemblies. We have employed dissipative particl...
1707.04604v3
2017-07-27
SRF Theory Developments from the Center for Bright Beams
We present theoretical studies of SRF materials from the Center for Bright Beams. First, we discuss the effects of disorder, inhomogeneities, and materials anisotropy on the maximum parallel surface field that a superconductor can sustain in an SRF cavity, using linear stability in conjunction with Ginzburg-Landau and ...
1707.09025v1
2019-12-13
Strength, transformation toughening and fracture dynamics of rocksalt-structure Ti1-xAlxN (0 <= x <= 0.75) alloys
Ab initio-calculated ideal strength and toughness describe the upper limits for mechanical properties attainable in real systems and can, therefore, be used in selection criteria for materials design. We employ density-functional ab initio molecular dynamics (AIMD) to investigate the mechanical properties of defect-fre...
1912.06367v2
2015-04-02
Thermoelectric Signal Enhancement by Reconciling the Spin Seebeck and Anomalous Nernst Effects in Ferromagnet/Non-magnet Multilayers
The utilization of ferromagnetic (FM) materials in thermoelectric devices allows one to have a simpler structure and/or independent control of electric and thermal conductivities, which may further remove obstacles for this technology to be realized. The thermoelectricity in FM/non-magnet (NM) heterostructures using an...
1504.00642v1
2018-07-02
Electron-electron interactions of the multi-Cooper-pairs in the 1D limit and their role in the formation of global phase coherence in quasi-one-dimensional superconducting nanowire arrays
Nanostructuring of superconducting materials to form dense arrays of thin parallel nanowires with significantly large transverse Josephson coupling has proven to be an effective way to increase the upper critical field of superconducting elements by as much as two orders of magnitude as compared to the corresponding bu...
1807.00611v1
2018-07-30
Tunable Thermal Energy Transport across Diamond Membranes and Diamond-Si Interfaces by Nanoscale Graphoepitaxy
The development of electronic devices, especially those that involve heterogeneous integration of materials, has led to increased challenges in addressing their thermal operational-temperature demands. The heat flow in these systems is significantly influenced or even dominated by thermal boundary resistance at interfa...
1807.11400v2
2019-10-28
Tailored Graphenic Structures Directly Grown on Titanium Oxide Boost the Interfacial Charge Transfer
The successful application of titanium oxide-graphene hybrids in the fields of photocatalysis, photovoltaics and photodetection strongly depends on the interfacial contact between both materials. The need to provide a good coupling between the enabling conductor and the photoactive phase prompted us to directly grow co...
1910.12667v1
2020-08-23
Nanofibril-mediated Fracture Resistance of Bone
Natural hard composites like human bone possess a combination of strength and toughness that exceeds that of their constituents and of many engineered composites. This augmentation is attributed to their complex hierarchical structure, spanning multiple length scales; in bone, characteristic dimensions range from nanos...
2008.09955v1
2020-10-28
Statistical analysis of the material, geometrical and imperfection characteristics of structural stainless steels and members
Traditional member-based two-step design approaches included in current structural codes for steel structures, as well as more recent system-based direct-design alternatives, require building rigorous structural reliability frameworks for the calibration of partial coefficients (resistance factors) to achieve specified...
2010.14777v2
2020-11-03
Fully-Compensated Ferrimagnetic Spin Filter Materials within the Cr$\textit{M}\textit{N}$Al Equiatomic Quaternary Heusler Alloys
XX'YZ equiatomic quaternary Heusler alloys (EQHA's) containing Cr, Al, and select Group IVB elements ($\textit{M}$ = Ti, Zr, Hf) and Group VB elements ($\textit{N}$ = V, Nb, Ta) were studied using state-of-the-art density functional theory to determine their effectiveness in spintronic applications. Each alloy is class...
2011.01389v1
2020-12-02
Strain-induced anion ordering in perovskite oxyfluoride films
Anionic ordering is a promising route to engineer physical properties in functional heteroanionic materials. A central challenge in the study of anion-ordered compounds lies in developing robust synthetic strategies to control anion occupation and in understanding the resultant implications for electronic structure. He...
2012.01221v1
2021-02-06
Multiple charge density waves and superconductivity nucleation at antiphase domain walls in the nematic pnictide Ba$_{1-x}$Sr$_{x}$Ni$_{2}$As$_{2}$
How superconductivity interacts with charge or nematic order is one of the great unresolved issues at the center of research in quantum materials. Ba$_{1-x}$Sr$_{x}$Ni$_{2}$As$_{2}$ (BSNA) is a charge ordered pnictide superconductor recently shown to exhibit a six-fold enhancement of superconductivity due to nematic fl...
2102.03592v2
2021-04-29
Competing magnetic interactions and magnetoresistance anomalies in cubic intermetallic compounds, Gd4RhAl and Tb4RhAl, and enhanced magnetocaloric effect for the Tb case
We report complex magnetic, magnetoresistance (MR) and magnetocaloric properties of Gd4RhAl and Tb4RhAl forming in the Gd4RhIn type cubic structure. Though the synthesis of the compounds was reported long ago, to our knowledge, no attempt was made to investigate the properties of these compounds. The present results of...
2104.14521v1
2021-10-12
Bridging the Band Gap: What Device Physicists Need to Know About Machine Learning
This article surveys the landscape of semiconductor materials and devices research for the acceleration of machine learning (ML) algorithms. We observe a disconnect between the semiconductor and device physics and engineering communities, and the digital logic and computer hardware architecture communities. The article...
2110.05910v2
2021-11-15
In situ Bragg coherent X-ray diffraction imaging of corrosion in a Co-Fe alloy microcrystal
Corrosion is a major concern for many industries, as corrosive environments can induce structural and morphological changes that lead to material dissolution and accelerate material failure. The progression of corrosion depends on nanoscale morphology, stress, and defects present. Experimentally monitoring this complex...
2111.07903v5
2021-12-16
Observation and manipulation of a phase separated state in a charge density wave material
The 1T polytype of TaS$_\textrm{2}$ has been studied extensively as a strongly correlated system. As 1T-TaS$_\textrm{2}$ is thinned towards the 2D limit, its phase diagram shows significant deviations from that of the bulk material. Optoelectronic maps of ultrathin 1T-TaS$_\textrm{2}$ have indicated the presence of non...
2112.09240v1
2022-03-17
Quasi-static crack front deformations in cohesive materials
When a crack interacts with material heterogeneities, its front distorts and adopts complex tortuous configurations that are reminiscent of the energy barriers encountered during crack propagation. As such, the study of crack front deformations is key to rationalize the effective failure properties of micro-structured ...
2203.09317v2
2022-05-11
Reversible Tuning of Superconductivity in Ion-Gated NbN Ultrathin Films by Self-Encapsulation with a High-$κ$ Dielectric Layer
Ionic gating is a powerful technique for tuning the physical properties of a material via electric field-induced charge doping, but is prone to introduce extrinsic disorder and undesired electrochemical modifications in the gated material beyond pure electrostatics. Conversely, reversible, volatile and electrostatic mo...
2205.05491v3
2022-06-07
Observation of surface superconductivity in a three-dimensional Dirac material
Superconductivity becomes more interesting when it encounters dimensional constraint or topology, because it is of importance for exploring exotic quantum phenomena or developing superconducting electronics. Here we report the coexistence of naturally formed surface superconducting state and three-dimensional topologic...
2206.03405v1
2022-10-03
Interwoven atypical quantum states in CeLiBi$_2$
We report the discovery of CeLiBi$_2$, the first example of a material in the tetragonal Ce$TX_2$ ($T$ = transition metal; $X$ = pnictogen) family wherein an alkali cation replaces the typical transition metal. Magnetic susceptibility and neutron powder diffraction measurements are consistent with a crystal-field $\Gam...
2210.01031v2
2022-11-27
Ionic Peltier Effect in Li-Ion Electrolytes
The coupled transport of charge and heat provide fundamental insights into the microscopic thermodynamics and kinetics of materials. We describe a sensitive ac differential resistance bridge that enables measurements of the temperature difference on two sides of a coin cell with a resolution of better than 10 uK. We us...
2211.14949v2
2023-03-28
A model for critical current effects in point-contact Andreev-reflection spectroscopy
It is well known that point-contact Andreev reflection spectroscopy provides reliable measurements of the energy gap(s) in a superconductor when the contact is in the ballistic or nearly-ballistic regime. However, especially when the mean free path of the material under study is small, obtaining ballistic contacts can ...
2303.15968v2
2023-05-12
Striation lines in intermittent fatigue crack growth in an Al alloy
Fatigue failure of crystalline materials is a difficult problem in science and engineering, and recent results have shown that fatigue crack growth can occur in intermittent jumps which have fat-tailed distributions. As fatigue crack propagation is known to leave markings -- called striations -- on the fracture surface...
2305.07460v1
2023-07-07
Observation of the anomalous Hall effect in a layered polar semiconductor
Progress in magnetoelectric materials is hindered by apparently contradictory requirements for time-reversal symmetry broken and polar ferroelectric electronic structure in common ferromagnets and antiferromagnets. Alternative routes could be provided by recent discoveries of a time-reversal symmetry breaking anomalous...
2307.03541v1
2023-08-23
Plastic deformation mechanisms during nanoindentation of W, Mo, V body-centered cubic single crystals and their corresponding W-Mo, W-V equiatomic random solid solutions
Deformation plasticity mechanisms in alloys and compounds may unveil the material capacity towards optimal mechanical properties. We conduct a series of molecular dynamics (MD) simulations to investigate plasticity mechanisms due to nanoindentation in pure tungsten, molybdenum and vanadium body-centered cubic single cr...
2308.12206v1
2023-09-08
Intralayer Negative Poisson's Ratio in Two-Dimensional Black Arsenic by Strain Engineering
Negative Poisson's ratio as the anomalous characteristic generally exists in artificial architectures, such as re-entrant and honeycomb structures. The structures with negative Poisson's ratio have attracted intensive attention due to their unique auxetic effect and many promising applications in shear resistant and en...
2309.04058v1
2023-10-04
Three-Sensor 2ω Method with Multi-directional Layout: A General Methodology for Measuring Thermal Conductivity of Solid Materials
Anisotropic thermal transport plays a key role in both theoretical study and engineering practice of heat transfer, but accurately measuring anisotropic thermal conductivity remains a significant challenge. To address this issue, we propose the three-sensor 2{\omega} method in this study, which is capable of accurately...
2310.02846v1
2023-10-25
Non-Destructive Imaging of Breakdown Process in Ferroelectric Capacitors Using \textit{In-situ} Laser-Based Photoemission Electron Microscopy
HfO$_2$-based ferroelectrics are one of the most actively developed functional materials for memory devices. However, in HfO$_2$-based ferroelectric devices, dielectric breakdown is a main failure mechanism during repeated polarization switching. Elucidation of the breakdown process may broaden the scope of application...
2310.16275v1
2023-11-16
Properties of Nb\_xTi\_{(1-x)}N thin films deposited on 300 mm silicon wafers for upscaling superconducting digital circuits
Scaling superconducting digital circuits requires fundamental changes in the current material set and fabrication process. The transition to 300 mm wafers and the implementation of advanced lithography are instrumental in facilitating mature CMOS processes, ensuring uniformity, and optimizing the yield. This study expl...
2311.09772v2
2024-03-18
Primary Defect Production in Doped Iron Grain Boundaries during Low Energy Collision Cascades
This study explores the intricate interactions between grain boundaries (GBs) and irradiation-induced defects in nanocrystalline iron, highlighting the role of dopants like copper. Utilizing molecular dynamics simulations, the research delineates how GB properties, such as GB energy and defect formation energies, influ...
2403.12257v1
2024-05-21
Engineering band structures of two-dimensional materials with remote moire ferroelectricity
The stacking order and twist angle provide abundant opportunities for engineering band structures of two-dimensional materials, including the formation of moire bands, flat bands, and topologically nontrivial bands. The inversion symmetry breaking in rhombohedral-stacked transitional metal dichalcogenides (TMDCs) endow...
2405.12811v1
1996-07-08
Dynamic Conductance in Quantum Hall Systems
In the framework of the edge-channel picture and the scattering approach to conduction, we discuss the low frequency admittance of quantized Hall samples up to second order in frequency. The first-order term gives the leading order phase-shift between current and voltage and is associated with the displacement current....
9607051v1
1997-02-12
Kondo Effect in High-T_c Cuprates
We study the Kondo effect due to the nonmagnetic impurity, e.g., Zn, in high-T_c cuprates based on the spin-change separated state. In the optimal or overdoped case with the Kondo screening, the residual resistivity is dominated by the spinons while the T-dependent part determined by the holons. This gives $\rho(T) = {...
9702103v2
1999-03-11
Anisotropic States of Two-Dimensional Electron Systems in High Landau Levels: Effect of an In-Plane Magnetic Field
We report the observation of an acute sensitivity of the anisotropic longitudinal resistivity of two-dimensional electron systems in half-filled high Landau levels to the magnitude and orientation of an in-plane magnetic field. In the third and higher Landau levels, at filling fractions nu=9/2, 11/2, etc., the in-plane...
9903196v2
1999-06-23
Micro-Raman and resistance measurements of epitaxial La0.7Sr0.3MnO3 films
The Channel-Spark method was used for deposition of highly oriented ferromagnetic La0.7Sr0.3MnO3 films on NdGaO3 substrates. It was found that additional oxygen decreases the film quality suppressing the Curie temperature and metal-insulator transition below the room temperature. To achieve the best quality of the film...
9906348v1
1999-07-19
Quantum Theory of Quantum-Hall Smectics
We propose a quantum stripe (smectic) coupled-Luttinger-liquid model for the anisotropic states which occur in two-dimensional electron systems with high-index partial Landau level filling, $\nu^{*} = \nu - \lbrack\nu\rbrack$. Perturbative renormalization group calculations establish that interaction terms neglected in...
9907278v1
1999-10-14
Electrical Noise From Phase Separation In Pr2/3Ca1/3MnO3 Single Crystal
Low frequency electrical noise measurements have been used to probe the electronic state of the perovskite-type manganese oxide Pr2/3Ca1/3MnO3 versus temperature and in the vicinity of the field-induced transition from the insulating, charge-ordered state (I-CO) to the metallic, ferromagnetic state (M-F). At high tempe...
9910204v1
1999-12-20
Oxygen isotope effects in high-quality thin films of manganites: Quantitative constraints on the physics of manganites
Oxygen isotope effects on the transport properties have been studied in high-quality epitaxial thin films of La_{0.75}Ca_{0.25}MnO_{3} and Nd_{0.7}Sr_{0.3}MnO_{3}. In the paramagnetic state, the resistivity can be well fitted by \rho (T) = (A/\sqrt{T})\exp(E_{\rho}/k_{B}T) with the parameters A and E_{a} depending stro...
9912355v1
2000-05-03
The doping dependence of T* - what is the real high-Tc phase diagram?
Underdoped high-Tc superconductors are frequently characterised by a temperature, T*, below which the normal-state pseudogap opens. Two different "phase diagrams" based on the doping (p) dependence of T* are currently considered: one where T* falls to zero at a critical doping state and the other where T* merges with T...
0005063v2
2000-07-13
Exclusion of quantum coherence as the origin of the 2D metallic state in high-mobility silicon inversion layers
The temperature and density dependence of the phase coherence time $\tau_\phi$ in high-mobility silicon inversion layers was determined from the magnetoresistivity due to weak localization. The upper temperature limit for single-electron quantum interference effects was delineated by comparing $\tau_\phi$ with the mome...
0007230v3
2001-02-22
Magnetoresistivity and Complete $H_{c2}(T)$ in $MgB_2$
Detailed magneto-transport data on dense wires of $MgB_2$ are reported for applied magnetic fields up to 18 T. The temperature and field dependencies of the electrical resistivity are consistent with $MgB_2$ behaving like a simple metal and following a generalized form of Kohler's rule. In addition, given the generally...
0102413v2
2001-08-17
Entropy of vortex cores on the border of the superconductor-to-insulator transition in an underdoped cuprate
We present a study of Nernst effect in underdoped $La_{2-x}Sr_xCuO_4$ in magnetic fields as high as 28T. At high fields, a sizeable Nernst signal was found to persist in presence of a field-induced non-metallic resistivity. By simultaneously measuring resistivity and the Nernst coefficient, we extract the entropy of vo...
0108277v2
2002-03-07
Pseudogap and Conduction Dimensionalities in High-T_c Superconductors
The nature of normal state charge-carriers' dynamics and the transition in conduction and gap dimensionalities between 2D and 3D for YBa_2 Cu_3 O_{7-delta} and Bi_2 Sr_2 Ca_{1-x} Y_x Cu_2 O_8 high-T_c superconductors were described by computing and fitting the resistivity curves, rho(T,delta,x). These were carried out ...
0203164v8
2002-03-07
The Onset of Anisotropic Transport of Two-Dimensional Electrons in High Landau Levels: An Isotropic-to-Nematic Liquid Crystal Phase Transition?
The recently discovered anisotropy of the longitudinal resistance of two-dimensional electrons near half filling of high Landau levels is found to persist to much higher temperatures T when a large in-plane magnetic field B|| is applied. Under these conditions we find that the longitudinal resistivity scales quasi-line...
0203174v1
2003-05-21
Magnetoresistive response of a high mobility 2DES under electromagnetic wave excitation
Oscillations of the resistance observed under electromagnetic wave excitation in the high mobility GaAs/AlGaAs 2DES are examined as a function of the radiation frequency and the power, utilizing an empirical lineshape based on exponentially damped sinusoids. The fit-analysis indicates the resistance oscillation frequen...
0305507v2
2003-07-15
Bolometric technique for high-resolution broadband microwave spectroscopy of ultra-low-loss samples
A novel low temperature bolometric method has been devised and implemented for high-precision measurements of the microwave surface resistance of small single-crystal platelet samples having very low absorption, as a continuous function of frequency. The key to the success of this non-resonant method is the in-situ use...
0307340v1
2003-09-26
Metastable Resistance Anisotropy Orientation of Two-Dimensional Electrons in High Landau Levels
In half-filled high Landau levels, two-dimensional electron systems possess collective phases which exhibit a strongly anisotropic resistivity tensor. A weak, but as yet unknown, rotational symmetry-breaking potential native to the host semiconductor structure is necessary to orient these phases in macroscopic samples....
0309625v2
2003-12-31
Single-electron transistors in electromagnetic environments
The current-voltage (I-V) characteristics of single-electron transistors (SETs) have been measured in various electromagnetic environments. Some SETs were biased with one-dimensional arrays of dc superconducting quantum interference devices (SQUIDs). The purpose was to provide the SETs with a magnetic-field-tunable env...
0312726v2
2004-08-19
Charge dynamics of Ca_{2-x}Na_{x}CuO_{2}Cl_{2} as a correlated electron system with the ideal tetragonal lattice
We report the reflectivity and the resistivity measurement of Ca_{2-x}Na_{x}CuO_{2}Cl_{2} (CNCOC), which has a single-CuO2-plane lattice with no orthorhombic distortion. The doping dependence of the in-plane optical conductivity spectra for CNCOC is qualitatively the same to those of other cuprates, but a slight differ...
0408423v1
2004-11-17
Spin-fluctuation dominated electrical transport of Ni3Al at high pressure
We present the first study of a magnetic quantum phase transition in the itinerant-electron ferromagnet Ni3Al at high pressures. Electrical resistivity measurements in a diamond anvil cell at hydrostatic pressures up to 100 kbar and temperatures as low as 50 mK indicate that the Curie temperature collapses towards abso...
0411451v1
2004-12-27
Fiske steps studied with flux-flow resistance oscillation in a narrow stack of Bi2Sr2CaCu2O8+d junctions
We have experimentally investigated the fluxon dynamics in a narrow Bi2Sr2CaCu2O8+d stack with junction length L~1.8 um. As an evidence of high-frequency excitation by a collective cavity mode, under an (in-plane) external magnetic field, the current-voltage characteristics show prominent Fiske steps with the correspon...
0412690v3
2005-03-07
Quantum Hall Effect at 40 kelvin: Evidence of MacroscopicQuantization in the Extreme Soft Limit
Evidence of both fractional and integer quantum hall effects (QHE) in three dimensional bulk replica opal (250nm diameter) structures of non-crystalline carbon are presented. In a remarkably soft quantum limit of ~ 40K temperature and about one tesla of magnetic field clear hall steps, such as n= 2/3, 4/5, 1 and others...
0503166v1
2005-04-01
On the origin of multiple ordered phases in PrFe4P12
The nature of multiple electronic orders in skutterudite PrFe_4P_{12} is discussed on the basis of a model with antiferro-quadrupole (AFQ) interaction of \Gamma_3 symmetry. The high-field phase can be reproduced qualitatively provided (i) ferro-type interactions are introduced between the dipoles as well as between the...
0504014v2
2005-04-27
Influence of a Parallel Magnetic Field on Microwave Photoconductivity in a High-Mobility 2D Electron System
We have studied experimentally the influence of a parallel magnetic field ($B_{//}$) on microwave-induced resistance oscillations (MIRO) and zero-resistance states (ZRS) previously discovered in a high-mobility 2D electron system. We have observed a strong suppression of MIRO/ZRS by a modest $B_{//}\sim 0.5$ T. In Hall...
0504715v1
2005-05-25
Anisotropy, disorder, and superconductivity in CeCu2Si2 under high pressure
Resistivity measurements were carried out up to 8 GPa on single crystal and polycrystalline samples of CeCu2Si2 from differing sources in the homogeneity range. The anisotropic response to current direction and small uniaxial stresses was explored, taking advantage of the quasi-hydrostatic environment of the Bridgman a...
0505613v1
2005-07-06
Magnetoresistance and spin polarization in the insulating regime of a Si two-dimensional electron system
We have studied the magnetoresistance in a high-mobility Si inversion layer down to low electron concentrations at which the longitudinal resistivity $\rho_{xx}$ has an activated temperature dependence. The angle of the magnetic field was controlled so as to study the orbital effect proportional to the perpendicular co...
0507136v1
2006-05-22
Radiation-induced magnetoresistance oscillations in two-dimensional electron systems under bichromatic irradiation
We analyze the magnetoresistance $R_{xx}$ oscillations in high-mobility two-dimensional electron systems induced by the combined driving of two radiation fields of frequency $\omega_1$ and $\omega_2$, based on the balance-equation approach to magnetotransport for high-carrier-density systems in Faraday geometry. It is ...
0605521v1
2006-06-19
Metallic State in Cubic FeGe beyond its Quantum Phase Transition
We report on results of electrical resistivity and structural investigations on the cubic modification of FeGe under high pressure. The long-wavelength helical order ($T_C=280$ K) is suppressed at a critical pressure $p_c\approx 19$ GPa. An anomaly in the resistivity data at $T_X(p)$ and strong deviations from a Fermi-...
0606493v1
2007-03-23
Giant asymmetry of the longitudinal magnetoresistance in high-mobility two-dimensional electron gas on a cylindrical surface
A giant asymmetry in the magnetoresistance was revealed in high-mobility, two-dimensional electron gas on a cylindrical surface. The longitudinal resistance along the magnetic-field gradient impressed by the surface curvature was found to vanish if measured along one of the edges of the curved Hall bar. If the external...
0703623v1
2006-12-17
A New GEM-like Imaging Detector with Electrodes Coated with Resistive Layers
We have developed and tested several prototypes of GEM-like detectors with electrodes coated with resistive layers: CuO or CrO. These detectors can operate stably at gains close to 10E5 and they are very robust. We discovered that the cathodes of these detectors could be coated by CsI layers and in such a way the detec...
0612166v1
1997-02-07
The Landauer Resistance and Band Spectra for the Counting Quantum Turing Machine
The generalized counting quantum Turing machine (GCQTM) is a machine which, for any N, enumerates the first $2^{N}$ integers in succession as binary strings. The generalization consists of associating a potential with read-1 steps only. The Landauer Resistance (LR) and band spectra were determined for the tight binding...
9702021v1
2008-06-17
Structural transition and anisotropic properties of single crystalline SrFe2As2
Plate-like single crystals of SrFe2As2 as large as 3x3x0.5 mm3 have been grown out of Sn flux. The SrFe2As2 single crystals show a structural phase transition from a high temperature tetragonal phase to a low temperature orthorhombic phase at To = 198 K, and do not show any sign of superconductivity down to 1.8 K. The ...
0806.2711v1
2008-08-29
On collisions driven negative energy waves and Weibel instability of a relativistic electron beam in a quasi-neutral plasma
A new quasi-neutral model describing the Weibel instability of a high-current relativistic beam propagating through a resistive plasma is developed. It treats beam electrons as kinetic particles, and ambient plasma as a non-relativistic fluid. For a finite-temperature beam, a new class of negative energy magneto-sound ...
0808.4078v2
2008-10-05
Anisotropic magnetic and superconducting properties of pure and Co-doped CaFe$_2$As$_2$ single crystals
We report anisotropic dc magnetic susceptibility $\chi(T)$, electrical resistivity $\rho(T)$, and heat capacity $C(T)$ measurements on the single crystals of CaFe$_{2-x}$Co$_x$As$_2$ for $x$ = 0 and 0.06. Large sized single crystals were grown by the high temperature solution method with Sn as the solvent. For the pure...
0810.0848v2
2008-11-17
Possible superconductivity above 25 K in single crystalline Co-doped BaFe$_{2}$As$_{2}$
We present superconducting properties of single crystalline Ba(Fe$_{0.9}$Co$_{0.1}$)$_{2}$As$_{2}$ by measuring magnetization, resistivity, upper critical field, Hall coefficient, and magneto-optical images. The magnetization measurements reveal fish-tail hysteresis loop at high temperatures and relatively high critica...
0811.2621v1
2008-12-05
High-T_c superconductivity induced by doping rare earth elements into CaFeAsF
We have successfully synthesized the fluoride-arsenide compounds Ca$_{1-x}$RE$_x$FeAsF (RE=Nd, Pr; x=0, 0.6). The x-ray powder diffraction confirmed that the main phases of our samples are Ca$_{1-x}$RE$_x$FeAsF with the ZrCuSiAs structure. By measuring resistivity, superconductivity was observed at 57.4 K in Nd-doped a...
0812.1192v1
2009-01-14
AC Josephson effect in the long voltage-biased SINIS junction
Theory of non-stationary coherent effects is developed for superconductor-normal-superconductor (SNS) structures with relatively strong normal scattering on S/N interfaces (interface resistance is large compared to intrinsic resistance of N metal). Analitical expressions are found for the time-dependent anomalous Green...
0901.1966v2
2009-03-04
Observation of a non-Ohmic Hall resistivity above the critical temperature in the high-temperature superconductor YBa$_{2}$Cu$_{3}$O$_{7-δ}$
Investigations of the resistivity and the Hall effect as a function of electric field and temperature in the normal state and upper part of the superconducting transition of an optimally doped, very thin film of YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ are reported. Using a fast pulsed-current technique allowed to reduce the se...
0903.0725v1
2009-04-17
EuFe$_2$As$_2$ under high pressure: an antiferromagnetic bulk superconductor
We report the ac magnetic susceptibility $\chi_{ac}$ and resistivity $\rho$ measurements of EuFe$_2$As$_2$ under high pressure $P$. By observing nearly 100% superconducting shielding and zero resistivity at $P$ = 28 kbar, we establish that $P$-induced superconductivity occurs at $T_c \sim$~30 K in EuFe$_2$As$_2$. $\rho...
0904.2618v2
2009-06-29
Spontaneous non-steady magnetic reconnection within the solar environment
This work presents a 2.5-dimensional simulation study of the instability of current-sheets located in a medium with a strong density variation along the current layer. The initial force-free configuration is observed to undergo a two-stage evolution consisting of an abrupt regime transition from a slow to a fast reconn...
0906.5382v1
2009-07-17
Performances of linseed oil-free bakelite RPC prototypes with cosmic ray muons
A comparative study has been performed on Resistive Plate Chambers (RPC) made of two different grades of bakelite paper laminates, produced and commercially available in India. The chambers, operated in the streamer mode using argon, tetrafluroethane and isobutane in 34:59:7 mixing ratio, are tested for the efficiency ...
0907.2976v1
2009-10-21
"Bad Metal" Conductivity of Hard Core Bosons
Two dimensional hard core bosons suffer strong scattering in the high temperature resistive state at half filling. The dynamical conductivity is calculated using non perturbative tools such as continued fractions, series expansions and exact diagonalization. We find a large temperature range with linearly increasing re...
0910.4158v2
2009-12-16
Distributed control of reactive power flow in a radial distribution circuit with high photovoltaic penetration
We show how distributed control of reactive power can serve to regulate voltage and minimize resistive losses in a distribution circuit that includes a significant level of photovoltaic (PV) generation. To demonstrate the technique, we consider a radial distribution circuit with a single branch consisting of sequential...
0912.3281v1
2010-03-26
Strong carrier-scattering in iron-pnictide superconductors with highest Tc obtained from charge transport experiments
Characteristic normal-state charge transport is found in the oxygen-deficient iron-arsenides LnFeAsO1-y (Ln: La and Nd) with the highest Tc's among known Fe-based superconductors. The effect of "doping" in this system is mainly on the carrier scattering, quite distinct from that in high-Tc cuprates. In the superconduct...
1003.5039v1
2010-04-14
Electron-hole coexistence in disordered graphene probed by high-field magneto-transport
We report on magneto-transport measurement in disordered graphene under pulsed magnetic field of up to 57T. For large electron or hole doping, the system displays the expected anomalous Integer Quantum Hall Effect (IQHE) specific to graphene up to filling factor $\nu=2$. In the close vicinity of the charge neutrality p...
1004.2356v1
2010-05-30
Loss-resistant state teleportation and entanglement swapping using a quantum-dot spin in an optical microcavity
We present a scheme for efficient state teleportation and entanglement swapping using a single quantum-dot spin in an optical microcavity based on giant circular birefringence. State teleportation or entanglement swapping is heralded by the sequential detection of two photons, and is finished after the spin measurement...
1005.5545v2
2010-09-28
Vortex Phase Diagram of Layered Superconductor Cu0.03TaS2 for H || c
The magnetization and anisotropic electrical transport properties have been measured in high quality Cu0.03TaS2 single crystal. A pronounced peak effect has been observed, indicating that the high quality and homogeneity are vital to peak effect. A kink has been observed in the magnetic field H dependence of the in-pla...
1009.5449v2
2010-11-27
Performance of Glass Resistive Plate Chambers for a high granularity semi-digital calorimeter
A new design of highly granular hadronic calorimeter using Glass Resistive Plate Chambers (GRPCs) with embedded electronics has been proposed for the future International Linear Collider (ILC) experiments. It features a 2-bit threshold semi-digital read-out. Several GRPC prototypes with their electronics have been succ...
1011.5969v2
2010-12-13
Self-consistent calculation of the single particle scattering rate in high $Tc$ cuprates
The linear temperature dependence of the resistivity above the optimal doping is a longstanding problem in the field of high temperature superconductivity in cuprates. In this paper, we investigate the effect of gauge fluctuations on the momentum relaxation time and the transport scattering rate within the slave boson ...
1012.2764v1
2011-03-17
Quantum-Classical Crossover and Apparent Metal-Insulator Transition in a Weakly Interacting 2D Fermi Liquid
We report the observation of a parallel magnetic field induced metal-insulator transition (MIT) in a high-mobility two-dimensional electron gas (2DEG) for which spin and localization physics most likely play no major role. The high-mobility metallic phase at low field is consistent with the established Fermi liquid tra...
1103.3496v2
2011-05-05
Pairing Fluctuations and Anomalous Transport Above the BCS-BEC Crossover in the Two Dimensional Attractive Hubbard Model
A Fermi liquid with weak attractive interaction undergoes a BCS transition to a superconductor with reducing temperature. With increasing interaction strength, the thermal transition is progressively modified as the high temperature `metallic' phase develops a pseudogap due to pairing fluctuations and the resistivity a...
1105.1156v1
2011-11-28
Evolution of a metastable phase with a magnetic phase coexistence phenomenon and its unusual sensitivity to magnetic field cycling in the alloys Tb5-xLuxSi3 (x <= 0.7)
Recently, we reported an anomalous enhancement of the positive magnetoresistance beyond a critical magnetic field in Tb5Si3 in the magnetically ordered state, attributable to 'inverse metamagnetism'. This results in unusual magnetic hysteresis loops for the pressurized specimens, which are relevant to the topic of 'ele...
1111.6368v1
2012-10-09
Interdependence of Electric Discharge and The Magnetorotational Instability in Protoplanetary Disks
We study how the magnetorotational instability (MRI) in protoplanetary disks is affected by the electric discharge caused by the electric field in the resistive MHD. We have performed three-dimensional shearing box simulations with various values of plasma beta and electrical breakdown models. We find the self-sustainm...
1210.2508v2
2012-12-18
Microwave properties of superconducting atomic-layer deposited TiN films
We have grown superconducting TiN films by atomic layer deposition with thicknesses ranging from 6 to 89 nm. This deposition method allows us to tune the resistivity and critical temperature by controlling the film thickness. The microwave properties are measured, using a coplanar-waveguide resonator, and we find inter...
1212.4434v1
2013-04-22
Persistent non-metallic behavior in Sr2IrO4 and Sr3Ir2O7 at high pressures
Iridium-based 5d transition-metal oxides are attractive candidates for the study of correlated electronic states due to the interplay of enhanced crystal-field, Coulomb and spin-orbit interaction energies. At ambient pressure, these conditions promote a novel Jeff = 1/2 Mott insulating state, characterized by a gap of ...
1304.5864v2
2013-08-28
Normal-state charge dynamics in doped BaFe2As2: Roles of doping and necessary ingredients for superconductivity
We carried out a comparative study of the in-plane resistivity and optical spectrum of doped BaFe2As2 and investigated the doping evolution of the charge dynamics. For BaFe2As2, charge dynamics is incoherent at high temperatures. Electron (Co) and isovalent (P) doping into BaFe2As2 increase coherence of the system and ...
1308.6133v1
2014-04-07
Crystal structure and physical properties of EuPtIn$_{4}$ intermetallic antiferromagnet
We report the synthesis of EuPtIn$_{4}$ single crystalline platelets by the In-flux technique. This compound crystallizes in the orthorhombic Cmcm structure with lattice parameters $a=4.542(1)$ \AA, $b=16.955(2)$ \AA$\,$ and $c=7.389(1)$ \AA. Measurements of magnetic susceptibility, heat capacity, electrical resistivit...
1404.1660v1
2014-04-14
High temperature superconducting FeSe films on SrTiO3 substrates
Interface enhanced superconductivity at two dimensional limit has become one of most intriguing research directions in condensed matter physics. Here, we report the superconducting properties of ultra-thin FeSe films with the thickness of one unit cell (1-UC) grown on conductive and insulating SrTiO3 (STO) substrates. ...
1404.3464v2
2014-04-16
Magnetic Ordering at Anomalously High Temperatures in Dy at Extreme Pressures: a New Kondo-Lattice State?
In an attempt to destabilize the magnetic state of the heavy lanthanides Dy and Gd, extreme pressures were applied in an electrical resistivity measurement to 157 GPa over the temperature range 5 - 295 K. The magnetic ordering temperature $T_{\text{o}}$ and spin-disorder resistance $R_{sd}$ of Dy, as well as the superc...
1404.4256v3
2014-05-14
Theory of universal incoherent metallic transport
In an incoherent metal, transport is controlled by the collective diffusion of energy and charge rather than by quasiparticle or momentum relaxation. We explore the possibility of a universal bound $D \gtrsim \hbar v_F^2/(k_B T)$ on the underlying diffusion constants in an incoherent metal. Such a bound is loosely moti...
1405.3651v3
2014-05-14
Linear Resistivity from Non-Abelian Black Holes
Starting with the holographic p-wave superconductor, we show how to obtain a finite DC conductivity through a non-abelian gauge transformation. The translational symmetry is preserved. We obtain phenomenological similarities with high temperature cuprate superconductors. Our results suggest that a lattice or impurities...
1405.3714v4
2014-06-10
Nonlinear transport and noise thermometry in quasi-classical ballistic point contacts
We study nonlinear transport and non-equilibrium current noise in quasi-classical point contacts (PCs) defined in a low-density high-quality two-dimensional electron system in GaAs. At not too high bias voltages $V$ across the PC the noise temperature is determined by a Joule heat power and almost independent on the PC...
1406.2481v2
2014-12-11
Transition-Metal Substitutions in Iron Chalcogenides
The $ab$-plane resistivity and Hall effect are studied in Fe$_{1-y}$M$_y$Te$_{0.65}$Se$_{0.35}$ single crystals doped with two transition metal elements, M = Co or Ni, over a wide doping range, $0 \leq y \leq 0.2$. The superconducting transition temperature, $T_{c}$, reaches zero for Co at $y \simeq 0.14$ and for Ni at...
1412.3599v1