Numerical Investigation of the Dynamics of a Thin Film Type II Superconductor with and without Disorder

Abstract

The equilibrium dynamics of a thin film type II superconductor with spherical geometry are investigated numerically in a simulation based on the lowest Landau level approximation to the time-dependent Ginzburg-Landau equation. Both the static and time-dependent density-density correlation functions of the superconducting order parameter have been investigated. As the temperature is lowered the correlation length, the length-scale over which the vortices have short-range crystalline order, increases but the introduction of quenched random disorder reduces this correlation length. We see no signs of a phase transition in either the pure or the disordered case. For the disordered system there is no evidence for the existence of a Bragg glass phase with quasi long-range correlations. The dynamics in both the pure and disordered systems is activated, and the barrier of the relaxation mechanism grows linearly with the correlation length. The self-diffusion time scale of the vortices was also measured and has the same temperature dependence as that of the longest time scales found in the time dependent density-density correlation function. The dominant relaxation mechanism observed is a change in orientation of a correlated region of size of the correlation length. A scaling argument is given to explain the value of the barrier exponent.

10 pages incl. 9 Postscript figures, RevTex) submitted to Phys. Rev. B

References in corpus (6)

• Elastic Theory of pinned flux lattices
• Two-Dimensional Vortex Lattice Melting
• Vortices in a Thin Film Superconductor with a Spherical Geometry
• Absence of the Transition into Abrikosov Vortex State of Two-Dimensional Type-II Superconductor with Weak Pinning
• Parquet Graph Resummation Method for Vortex Liquids
• Monte Carlo Studies of the Two-Dimensional Vortex Liquid: Absence of Transition and Dynamical Properties

Cited by in corpus (5)

• The Ginzburg-Landau Theory of Type II superconductors in magnetic field
• Numerical studies of the phase diagram of layered type II superconductors in a magnetic field
• Flux-lattice melting in two-dimensional disordered superconductors
• Langevin vortex dynamics for a layered superconductor in the lowest Landau level approximation
• On the nature of the phase transitions in two-dimensional type II superconductors