Peculiarities of the Resistive State in Mo/Si Superlattices in a Magnetic Field

2003 ◽  
Vol 17 (10n12) ◽  
pp. 627-634 ◽  
Author(s):  
A. Yu. Aladyshkin ◽  
A. Yu. Klimov ◽  
M. A. Kucherenko ◽  
V. V. Kurin ◽  
V. L. Mironov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Temperature Dependence ◽  
Transport Properties ◽  
Transverse Magnetic ◽  
Zero Magnetic Field ◽  
Experimental Investigations ◽  
Resistive State ◽  
Sharp Change ◽  
Superconducting Transition ◽  
Multilayered Structures

The experimental investigations of the transport properties of the superconducting Mo/Si multilayered structures are presented. The observed anisotropy of the electrical resistivity of Mo/Si bridges in a weak magnetic fields H ≲ 5 × 102 Oe is in agreement with the data reported earlier. However, for the Mo/Si microbridges with the width 2 μm in a transverse magnetic field H ≳ 5 × 102 Oe we have found out that the temperature dependence of the in-plane resistivity R(T) demonstrates a sharp change of the resistivity at a certain critical temperature T* < Tc, where Tc is the superconducting transition temperature in a zero magnetic field. For a parallel magnetic field this step-like behavior has not been revealed; we neither observed this effect in wider bridges. The comparison of the transport properties and the nonlinear microwave characteristics is presented. A possible origin of this unusual temperature dependence of R(T) is proposed.

scholarly journals Spin-Orbit Coupling Effects on Transport Properties of Electronic Lieb Lattice in the Presence of Magnetic Field

2021 ◽  
Author(s):  
Elham Sadeghi ◽  
Hamed Rezania
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Temperature Dependence ◽  
Transport Properties ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Lieb Lattice ◽  
Thermal Conductivities

Abstract In this paper, the transport properties of a two-dimensional Lieb lattice that is a line-centered square lattice are investigated in the presence of magnetic field and spin-orbit coupling. Specially, we address the temperature dependence of electrical and thermal conductivities as well as Seebeck coefficient due to spin-orbit interaction. We have exploited Green’s function approach in order to study thermoelectric and transport properties of Lieb lattice in the context of Kane-Mele model Hamiltonian. The results for Seebeck coefficient show the sign of thermopower is positive in the presence of spin-orbit coupling. Also the temperature dependence of transport properties indicates that the increase of spin-orbit coupling leads to decrease thermal conductivity however the decrease of gap 1 parameter causes the reduction of thermal conductivity. There is a peak in temperature dependence of thermal conductivity for all values of magnetic fields and spin-orbit coupling strengths. Both electrical and thermal conductivities increase with increasing the temperature at low amounts of temperature due to the increasing of transition rate of charge carriers and excitation of them to the conduction bands. Also we have studied the temperature dependence of spin susceptibility of Lieb monolayer due to both spin orbit coupling and magnetic field factors in details.

scholarly journals DISSIPATIVE 2D ELECTRON ON A TORUS IN EXTERNAL MAGNETIC FIELD: TRANSPORT PROPERTIES AND MAGNETIC TRANSLATIONS

1995 ◽  
Vol 09 (24) ◽  
pp. 3229-3240 ◽  
Author(s):  
G. CRISTOFANO ◽  
D. GIULIANO ◽  
G. MAIELLA ◽  
L. VALENTE
Keyword(s):  
Magnetic Field ◽  
Wave Function ◽  
Transport Properties ◽  
Ground State ◽  
Large Time ◽  
Transverse Magnetic ◽  
The Novel ◽  
Translation Operators ◽  
Magnetic Translation ◽  
Electron Ground State

The effect of dissipation on the electron ground state wave function on a torus in the presence of an external transverse magnetic field is analyzed on large time scales [Formula: see text]. Its extension to the multiparticle center of the mass wave function is also given. The novel transport properties of the system are then studied by applying Laughlin gauge argument with the use of the magnetic translation operators.

scholarly journals Nonlinear Response of a Superconductor of the Bi-Sr-Ca-Cu-O System to an Alternating Magnetic Field in the Superconducting Transition Temperature Range

2018 ◽  
Vol 185 ◽  
pp. 08005
Author(s):  
Alexander Sergeev ◽  
Igor Golev ◽  
Victoria Gvozdevskaya ◽  
Anastasia Barkalova
Keyword(s):  
Magnetic Field ◽  
Nonlinear Response ◽  
Alternating Magnetic Field ◽  
Resistive State ◽  
Superconducting Transition ◽  
Critical Temperatures ◽  
Temperature Range ◽  
Nonlinear Properties ◽  
Current Voltage ◽  
Current Voltage Characteristics

The nonlinear response of the superconductor of the Bi-Sr-Ca-Cu-O system in the temperature range of the superconducting transition under the action of a harmonic alternating magnetic field is experimentally studied. For multiphase superconductors having in their volume regions with distinct critical temperatures, the effect of odd harmonics in the response signal is observed. The contribution of crystallites and the system of weak bonds between the crystallites in the nonlinear response is singled out. It was found that the nonlinear properties of the investigated samples in the resistive state are determined mainly by the nonlinear current-voltage characteristics of the system of weak bonds between the crystallites.

Scaling of Resistivities in MgB2

2006 ◽  
Vol 47 ◽  
pp. 113-117
Author(s):  
Petr Vašek
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Critical Temperature ◽  
External Magnetic Field ◽  
Transport Current ◽  
Zero Magnetic Field ◽  
Superconducting Transition ◽  
Hall Voltage ◽  
Transition Range ◽  
Width Of Superconducting Transition

Longitudinal and transverse voltages have been measured on thin films of MgB2 with different width of superconducting transition range. The study has been performed in zero and nonzero external magnetic fields. The non-zero transverse voltage has been observed in close vicinity of the critical temperature in zero external magnetic field while far enough from Tc this voltage has been zero. In magnetic field it merges into transverse voltage which is an even function with respect to the direction of the field. Usual Hall voltage starts to appear with increasing magnetic field. At the highest field the even voltage disappears and only the Hall voltage is measurable i.e. the transverse even voltage is suppressed with increasing magnetic field and increasing transport current as well. New scaling between transverse and longitudinal resistivities has been observed in the form ρxy~dρxx/dT . This correlation is valid not only in the zero magnetic field but also in nonzero magnetic field where transverse even voltage can be detected. Several models trying to explain observed results are discussed. The most promising seems to be guided motion of the vortices.

Magnetic Prehistory in the Heat Capacity of the Low-Temperature Superconductors

2015 ◽  
Vol 233-234 ◽  
pp. 741-744
Author(s):  
Sergey Mikhailovich Podgornykh
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
External Magnetic Field ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Zero Magnetic Field ◽  
Zero Field ◽  
Ring Specimen ◽  
Trapped Flux ◽  
The Magnetic Field

Effect of the magnetic prehistory on the temperature dependence of the heat capacity of the superconducting Pb, La, Sn. has been studied. As soon as the external magnetic field riches the valueHext=HCthe superconductivity is completely destroyed. The trapped flux was produced in the ring specimen after the magnetic field was turned off atT<TC. We observed a difference of the value of the heat capacity between zero field cooled (ZFC) and field cooled (FC) states in zero magnetic field for the ring specimen. It is found that the FC heat capacity is smaller than the heat capacity both in the normal and in superconducting states.

ZERO FIELD ENTANGLEMENT IN DIPOLAR COUPLING SPIN SYSTEM AT NEGATIVE TEMPERATURE

2013 ◽  
Vol 11 (05) ◽  
pp. 1350050 ◽  
Author(s):  
GREGORY B. FURMAN ◽  
VICTOR M. MEEROVICH ◽  
VLADIMIR L. SOKOLOVSKY
Keyword(s):  
Magnetic Field ◽  
Temperature Dependence ◽  
Spin System ◽  
Dipolar Coupling ◽  
Negative Temperature ◽  
Absolute Temperature ◽  
Zero Magnetic Field ◽  
Entangled States ◽  
Zero Field ◽  
Negative Temperatures

A dipolar coupled spin system can achieve internal thermodynamic equilibrium states at negative absolute temperature. We study analytically and numerically the temperature dependence of the concurrence in a dipolar coupled spin-1/2 system in both nonzero and zero fields and show that, at negative temperatures, entangled states can exist even in zero magnetic field.

scholarly journals Macroscopic quantum tunneling of two coupled particles in the presence of a transverse magnetic field

2013 ◽  
Vol 91 (9) ◽  
pp. 722-727
Author(s):  
Solomon Akaraka Owerre
Keyword(s):  
Magnetic Field ◽  
Effective Action ◽  
Transverse Magnetic ◽  
Harmonic Oscillators ◽  
Zero Magnetic Field ◽  
Two Dimensional ◽  
Ohmic Dissipation ◽  
Linear Coupling ◽  
Dimensional Version ◽  
The One

Two coupled particles of identical mass but opposite charge are studied, with a constant transverse external magnetic field and an external potential, interacting with a bath of harmonic oscillators. We show that the problem cannot be mapped to a one-dimensional problem like the one in Ao (Phys. Rev. Lett. 72, 1898 (1994)), it strictly remains two-dimensional. We calculate the effective action both for the case of linear coupling to the bath and without a linear coupling using imaginary time path integral at finite temperature. At zero temperature we use Leggett’s prescription to derive the effective action. In the limit of zero magnetic field we recover a two-dimensional version of the result derived in Chudnovsky (Phys. Rev. B, 54, 5777 (1996)) for the case of two identical particles. We find that in the limit of strong dissipation, the effective action reduces to a two-dimensional version of the Caldeira–Leggett form in terms of the reduced mass and the magnetic field. The case of ohmic dissipation with the motion of the two particles damped by the ohmic frictional constant η is studied in detail.

Specific Heat Measurements on κ-(Bedt-Ttf)2Cu(Ncs)2

1989 ◽  
Vol 173 ◽  
Author(s):  
R. G. Goodrich ◽  
Jing-Chun Xu
Keyword(s):  
Magnetic Field ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Applied Magnetic Field ◽  
Degrees Of Freedom ◽  
Collective Modes ◽  
Superconducting Transition ◽  
Integral Expression ◽  
Lattice Specific Heat ◽  
Strong Coupling Superconductor

ABSTRACTWe have measured the specific heat of κ-(BEDT-TTF)2Cu(NCS)2 from 4 to 14 K. The superconducting transition at 9.4 K is observed in zero applied magnetic field and in a field of 0.3 T. Both the magnitude of the change in Cp at Tc and the temperature dependence of Cp below Tc indicate a strong coupling superconductor. If the lattice specific heat is assumed to contain contributions due to the eighteen vibrational degrees of freedom, the phonon contribution to the specific heat in our temperature range can be represented by a Debye integral expression with a Debye temperature of 95 K. A model of collective modes suggesting the origin of the eighteen degrees of freedom is presented.

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