Instabilities in the Flux Line Lattice of Anisotropic Superconductors

Дата и время публикации : 1996-01-31T17:07:33Z

Авторы публикации и институты :
A. M. Thompson (University of Manchester, U.K.)
M. A. Moore (University of Manchester, U.K.)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: Extensively revised paper, with modified analysis of elastic instabilities. Calculation of the lower critical field is included, and the presence of kinks in $H_{c_1}$ is seen to be related to the elastic instabilities. 29 pages including 16 figures, LaTeX with epsf style
Первичная категория: cond-mat

Все категории : cond-mat

Краткий обзор статьи: The stability of the flux line lattice has been investigated within anisotropic London theory. This is the first full-scale investigation of instabilities in the `chain’ state. It has been found that the lattice is stable at large fields, but that instabilities occur as the field is reduced. The field at which these instabilities first arise, $b^*(epsilon,theta)$, depends on the anisotropy $epsilon$ and the angle $theta$ at which the lattice is tilted away from the $c$-axis. These instabilities initially occur at wavevector $k^*(epsilon,theta)$, and the component of $k^*$ along the average direction of the flux lines, $k_z$, is always finite. As the instability occurs at finite $k_z$ the dependence of the cutoff on $k_z$ is important, and we have used a cutoff suggested by Sudbospace and Brandt. The instabilities only occur for values of the anisotropy $epsilon$ appropriate to a material like BSCCO, and not for anisotropies more appropriate to YBCO. The lower critical field $H_{c_1}(phi)$ is calculated as a function of the angle $phi$ at which the applied field is tilted away from the crystal axis. The presence of kinks in $H_{c_1}(phi)$ is seen to be related to instabilities in the equilibrium flux line structure.

Category: Physics