Effective "Penetration Depth" in the Vortex State of a d-wave Superconductor

TL;DR

This paper models the temperature and magnetic field dependence of the effective penetration depth in a d-wave superconductor's vortex state, explaining low-temperature experimental observations through a nonlocal London approach.

Contribution

It introduces a nonlocal London model to describe the penetration depth's behavior, revealing a crossover from linear to T^3 dependence at low temperatures.

Findings

Crossover from linear to T^3 dependence below T* rom ield dependence.

Explains low-temperature flattening of penetration depth curves.

Provides theoretical support for recent muon spin rotation experiments.

Abstract

The temperature and field dependence of the effective magnetic penetration depth in the vortex state of a d-wave superconductor, as measured by muon spin rotation experiments, is calculated using a nonlocal London model. We show that at temperatures below T^* \propto \sqrt{B}, the linear T-dependence of the effective penetration depth crosses over to a T^3-dependence. This could provide an explanation for the low temperature flattening of the effective penetration depth curves observed in a recent muon spin rotation experiment.