Surface barrier dominated transport in NbSe$_2$

TL;DR

This study reveals that in clean 2H-NbSe2 crystals, surface barriers dominate transport properties below Tc, with the critical current governed by vortex penetration at the surface rather than bulk pinning.

Contribution

It demonstrates that surface barriers control current flow and the resistive transition in NbSe2, highlighting the importance of surface effects over bulk pinning in these crystals.

Findings

Most current flows at the edges below Tc due to surface barriers.

Critical current is determined by vortex penetration through surface barriers.

Surface barriers dominate transport properties and resistive transition.

Abstract

Transport current distribution in clean 2$H$-NbSe$_{2}$ crystals is studied by measuring the self-induced magnetic field across the sample. Below $T_c$ most of the current flows at the edges of the crystals due to strong surface barriers, which are found to dominate the transport properties and the resistive transition. The measured critical current is determined by the critical current for vortex penetration through the surface barrier rather than by bulk pinning.