arXiv subjects

M. V. Feigel'man

Publications and source records attributed to M. V. Feigel'man.

75 records · Page 5Linked to original sources

arXiv1997

Parity Effect and Charge Binding Transition in Submicron Josephson Junction Arrays

We reconsider the issue of Berezinskii-Kosterlitz-Thouless (BKT) transition into an insulating state in the Coulomb-dominated Josephson junction arrays. We show that previously predicted picture of the Cooper-pair BKT transtion at T = T_2 is valid only under the condition that T_2 is considerably below the parity-effect temperature (which is usually almost 10 times below the value of superconductive transition temperature), and even in this case it is not a rigorous phase transition but only a crossover, whereas the real phase transition takes place at T_1 = T_2/4. Our theory is in agreement with available experimental data on Coulomb-dominated Josephson arrays and also sheds some light on the origin of unusual reentrant temperature dependence of resistivity in the array with nearly-criticial ratio of Coulomb to Josephson energies.

cond-mat.mes-hall↗

arXiv1996

Anomalous flux-flow dynamics in layered type-II superconductors at low temperatures

Low-temperature dissipation due to vortex motion in strongly anisotropic type-II superconductors with a moderate disorder ($Δ^2/E_F \ll \hbar/τ\ll Δ$) is shown to be determined by the Zener-type transitions between the localized electronic states in the vortex core. Statistics of these levels is described by the random matrix ensemble of the class C defined recently by Atland and Zirnbauer [cond-mat/9602137], so the vortex motion leads naturally to the new example of a parametric statistics of energy levels. The flux-flow conductivity $σ_{xx}$ is a bit lower than the quasiclassical one and {\it grows} slowly with the increase of the electric field.

cond-mat↗

arXiv1995

Sign Change of the Flux Flow Hall Effect in HTSC

A novel mechanism for the sign change of the Hall effect in the flux flow region is proposed. The difference $δn $ between the electron density at the center of the vortex core and that far outside the vortex causes the additional contribution to the Hall conductivity $δσ_{xy}=-δn ec/B$. This contribution can be larger than the conventional one in the dirty case $Δ(T)τ<1$. If the carrier density inside the core exceeds that far outside, a double sign change may occur as a function of temperature.

cond-mat↗