arXiv subjects

A. S. Mel'nikov

Publications and source records attributed to A. S. Mel'nikov.

75 records · Page 5Linked to original sources

arXiv1998

Quasiparticle spectrum near the gap node directions in the mixed state of d-wave superconductors

We report on a calculation of the quantized energy spectrum and quasiparticle eigenfunctions for low lying excitations in the mixed state of clean d-wave superconductors. Our study is based on an approximate analytical solution of the Bogolubov-de Gennes equations for both rectangular and triangular flux lattices with one of the primitive translations chosen parallel to the gap node direction. For excitations with momenta close to a certain gap node we have obtained a set of eigenfunctions which appear to be extended along the chosen gap node direction and localized along the perpendicular one on a scale determined by the intervortex distance. The periodic superfluid velocity field induces a band structure in the spectrum, which depends essentially on the vortex lattice geometry.

cond-mat.supr-con↗

arXiv1996

Inertial Mass and Viscosity of Tilted Vortex Lines in Layered Superconductors

The dynamics of tilted vortex lines in Josephson-coupled layered superconductors is considered within the time-dependent Ginzburg-Landau theory. The frequency and angular dependences of the complex-valued vortex mobility $μ$ are studied. The components of the viscosity and inertial mass tensors are found to increase essentially for magnetic field orientations close to the layers. For superconducting/normal metal multilayers the frequency ($ω$) range is shown to exist where the $μ^{-1}$ value depends logarithmically on $ω$.

cond-mat↗

arXiv1995

Dynamics of 2D pancake vortices in layered superconductors

The dynamics of 2D pancake vortices in Josephson-coupled superconducting/normal - metal multilayers is considered within the time-dependent Ginzburg-Landau theory. For temperatures close to $T_{c}$ a viscous drag force acting on a moving 2D vortex is shown to depend strongly on the conductivity of normal metal layers. For a tilted vortex line consisting of 2D vortices the equation of viscous motion in the presence of a transport current parallel to the layers is obtained. The specific structure of the vortex line core leads to a new dynamic behavior and to substantial deviations from the Bardeen-Stephen theory. The viscosity coefficient is found to depend essentially on the angle $γ$ between the magnetic field ${\bf B}$ and the ${\bf c}$ axis normal to the layers. For field orientations close to the layers the nonlinear effects in the vortex motion appear even for slowly moving vortex lines (when the in-plane transport current is much smaller than the Ginzburg-Landau critical current). In this nonlinear regime the viscosity coefficient depends logarithmically on the vortex velocity $V$.

cond-mat↗