Collective pinning of the vortex lattice by columnar defects in layered superconductors

TL;DR

This paper investigates how columnar defects influence vortex lattice behavior in layered superconductors, revealing a weakly superconducting Bose glass phase and a dimensional crossover without a peak effect in critical current.

Contribution

It provides a duality analysis of the frustrated XY model with columnar pins, identifying a Bose glass phase and explaining recent phase transition observations as a dimensional crossover.

Findings

Existence of a weak superconducting Bose glass phase

No peak effect in critical current density predicted

Phase transition as a dimensional crossover

Abstract

The mixed phase of layered superconductors with no magnetic screening is studied through a partial duality analysis of the corresponding frustrated XY model in the presence of random columnar pins. A small fraction of pinned vortex lines is assumed. Thermally induced plastic creep of the vortex lattice within isolated layers results in an intermediate Bose glass phase that exhibits weak superconductivity across layers in the limit of weak Josephson coupling. The correlation volume of the vortex lattice is estimated in the strongly-coupled Bose-glass regime at lower temperature. In the absence of additional point pins, no peak effect in the critical current density is predicted to occur on this basis as a function of the Josephson coupling. Also, the phase transition observed recently inside of the vortex-liquid phase of high-temperature superconductors pierced by sparse columnar defects is argued to be a sign of dimensional cross-over.