Transport properties of BSCCO crystals with and without surface barriers

TL;DR

This study investigates the transport properties of large BSCCO crystals with and without surface barriers, revealing how surface barriers influence resistance and phase transition behavior, and confirming Bragg glass theory predictions.

Contribution

It demonstrates the impact of surface barriers on transport measurements and provides experimental evidence supporting Bragg glass theory in large BSCCO crystals.

Findings

Surface barriers cause resistance drops and nonlinear effects in narrow samples.

Large crystals without surface barriers align with Bragg glass theory.

Surface barriers dominate resistive behavior at the phase transition.

Abstract

Large BSCCO crystals with electrical contacts positioned far from the edges are studied by transport measurements, then cut into the common narrow strip geometry, and remeasured. Instead of showing larger resistance, the narrow strip samples display a dramatic drop in the resistance, enhanced activation energies, and nonlinear characteristics due to strong surface barriers. The surface barriers also dominate the resistive drop at the first-order phase transition. Because the surface barriers are avoided in large crystals, we are able to probe the solid phase and find good agreement with the recent predictions of Bragg glass theory.