Journal Article

A study on the tunneling spectroscopy of an junction and an junction

Wan, Shaolong, Yan, Zhongbo

2014

Overview

We study the complete tunneling spectroscopy of a normal metal/p-wave superconductor junction ( ) and a normal metal/heterostructure superconductor junction ( ), using the Blonder-Tinkham-Klapwijk (BTK) method. We find that, for a p-wave superconductor with non-trivial topology, there exists a stable quantized zero-bias conductance peak, and for heterostructure superconductors with non-trivial topology, the emerging zero-bias conductance peak is non-quantized and usually has a considerable gap to the quantized value. Furthermore, the latter is sensitive to parameters, especially to spin-orbit coupling and the s-wave pairing potential. All results of the junction we obtained suggest that the observation of a small zero-bias conductance peak, instead of a quantized zero-bias conductance peak, in current tunneling experiments is a natural result. Based on the experiments' parameters, we find that only by varying the strength of the spin-orbit coupling to be several times smaller than the reported one, can the zero-bias conductance peak be as small as the reported one. Furthermore, the results we obtained suggest that both a stronger spin-orbit coupling and proximity s-wave superconductor with a relatively weaker pairing potential can produce a much more striking zero-bias conductance peak (compared to the experiments), even an almost quantized one. As s-wave superconductors are common in nature, this prediction can be verified using current experiments.

• Publisher: IOP Publishing
• Subject: 05.30.Rt / 14.80.Va / 73.63.Nm / normal metal / normal metal/heterostructure superconductor junction / normal metal/p-wave superconductor junction / tunneling spectroscopy / wave superconductor junction