Tunnelling in organic superconductors

TL;DR

This paper explores how tunnelling experiments can determine the pairing symmetry in organic superconductors, using a flexible theoretical framework to analyze experimental data for identifying unconventional superconductivity.

Contribution

It introduces a comprehensive theoretical scheme for analyzing tunnelling data in organic superconductors, capable of distinguishing different superconducting symmetries under various conditions.

Findings

Framework for calculating tunnelling current-voltage characteristics

Method to identify superconducting order parameter symmetry

Applicability to magnetic fields and finite temperatures

Abstract

We discuss the possibility of deciding on the symmetry of the superconducting phase in the organic superconductors (Bechgaard salts), using tunnelling experiments. We first briefly review the properties of organic superconductors, and the possibility to have unconventional (triplet) superconductivity in these systems. We then present a simple scheme for computing the full current-voltage characteristics for tunnelling experiments within the framework of the non-equilibrium Keldysh Green function formalism. This formalism is flexible enough to address different pairing symmetries combined with magnetic fields and finite temperatures at arbitrary bias voltages. We then discuss extensively how to apply these results to probe for the symmetry of the superconducting order parameter.