Optimum pinning of the vortex lattice in extremely type-II layered superconductors

Abstract

The two-dimensional (2D) vortex lattice in the extreme type-II limit is studied by Monte Carlo simulation of the corresponding 2D Coulomb gas, with identical pins placed at sites coinciding with the zero-temperature triangular vortex lattice. At weak pinning we find evidence for 2D melting into an intermediate hexatic phase. The strong pinning regime shows a Kosterlitz-Thouless transition, driven by interstitial vortex/anti-vortex excitations. A stack of such identical layers with a weak Josephson coupling models a layered superconductor with a triangular arrangement of columnar pins at the matching field. A partial duality analysis finds that layer decoupling of the flux-line lattice does not occur at weak pinning for temperatures below 2D melting.

5 pgs., 4 figs. To appear in PRB. Added size study of hexatic phase

References in corpus (1)

• Degradation of Phase Coherence by Defects in a Two-Dimensional Vortex Lattice

Cited by in corpus (6)

• Superconducting transition of a two-dimensional Josephson junction array in weak magnetic fields
• Defective Vortex Lattices in Layered Superconductors with Point Pins at the Extreme Type-II Limit
• Macroscopic Phase Coherence of Defective Vortex Lattices in Two Dimensions
• Collective pinning of the vortex lattice by columnar defects in layered superconductors
• Sublimated Decoupling of the Vortex Lattice in Extremely Type-II Layered Superconductors
• Critical Current of Type-II Superconductors in a Broken Bose Glass State