Peak-effect and surface crystal-glass transition for surface-pinned vortex array

TL;DR

This paper investigates the peak effect in surface-pinned vortices, revealing a transition from a weakly disordered crystal to a surface glass state through combined theoretical and experimental analysis.

Contribution

It introduces a new understanding of the peak effect linked to a surface glass transition in vortex matter, supported by experimental measurements on Nb crystals.

Findings

Sharp transition in vortex slippage length observed

Crossover from crystal to glass state identified

Experimental data supports theoretical model

Abstract

We present a theoretical and experimental study of the peak effect in the surface pinning of vortices. It is associated with a sharp transition in the vortex slippage length which we relate to a crossover from a weakly disordered crystal to a surface glass state. Experiments are performed on ion-beam etched Nb crystals. The slippage length is deduced from 1kHz-1MHz linear AC penetration depth measurements.