Andreev Bound States at the Interface of Antiferromagnets and d-wave Superconductors

TL;DR

This paper develops a transfer matrix approach to analyze Andreev bound states at interfaces between antiferromagnets and d-wave superconductors, revealing spin-splitting effects and conditions for charge current induction.

Contribution

It introduces a simple transfer matrix formalism to study bound states at antiferromagnet/d-wave superconductor interfaces, highlighting spin splitting and critical conditions for interface currents.

Findings

Zero energy mode at {110} interface is spin split by antiferromagnetism.

Superconducting order parameter breaking time reversal symmetry must exceed a critical value.

Charge current along the interface depends on the induced order parameter.

Abstract

We set up a simple transfer matrix formalism to study the existence of bound states at interfaces and in junctions between antiferromagnets and d-wave superconductors. The well-studied zero energy mode at the {110} interface between an insulator and a d-wave superconductor is spin split when the insulator is an antiferromagnet. This has as a consequence that any competing interface induced superconducting order parameter that breaks the time reversal symmetry needs to exceed a critical value before a charge current is induced along the interface.