Andreev reflection between a normal metal and the FFLO superconductor

TL;DR

This paper investigates Andreev reflection at a normal metal and FFLO superconductor interface, revealing conditions under which the process occurs and how it relates to the superconductor's properties.

Contribution

It introduces the concept of an Andreev window specific to FFLO superconductors, linking the reflection process to the superconductor's finite momentum and gap.

Findings

Andreev reflection occurs within a specific energy window.

The Andreev window's position relates to the superconductor's total momentum.

The process depends on the energy of incoming electrons.

Abstract

We consider a process of the Andreev reflection between a normal metal and the s-wave superconductor in the FFLO state. It is shown that the process takes place if the energy of the incoming electron is bound within the finite interval called the Andreev window. The position of the window determines the value of the non-zero total momentum of Cooper pairs and the value of the gap.