Rectification and rectification reversal of the surface critical current in type II superconductors in the mixed state

Abstract

A theory is developed to explain the values of the transport currents that can flow in very smooth single surfaces of some type II superconductors, such as in specimens with a triangular cross-section. The combined effect of the surface pinning, the surface barrier, and the Meissner currents is used to calculate the critical values for the transport currents. This deals with surface rectification, and in particular provides an explanation for rectification reversal, and the blunting of the angular dependence of the transport current under conditions of rectification reversal. The effects are of the correct magnitude to explain the experimental results.