Anomalous phase shift in a Josephson junction via an antiferromagnetic interlayer

D S Rabinovich,I V Bobkova,A M Bobkov

doi:10.1103/physrevresearch.1.033095

Abstract

The anomalous ground state phase shift in S/AF/S Josephson junctions in the presence of the Rashba SO-coupling is predicted and numerically investigated. It is found to be a consequence of the uncompensated magnetic moment at the S/AF interfaces. The anomalous phase shift exhibits a strong dependence on the value of the SO-coupling and the sublattice magnetization with the simultaneous existence of stable and metastable branches. It depends strongly on the orientation of the Neel vector with respect to the S/AF interfaces via the dependence on the orientation of the interface uncompensated magnetic moment, what opens a way to control the Neel vector by supercurrent in Josephson systems.

Highlights

The current-phase relation (CPR) of a Josephson junction (JJ) in its minimal form can be written as j = jc sin(φ − φ0), where jc > 0 is the critical current of the junction and φ is the phase difference between the superconducting leads
At first the spin quantization axis is chosen along the S/AF interface and the magnetic moment of A sites is directed along this axis, while the moment of B sites is the opposite
Our results demonstrate that in the presence of the uncompensated interface magnetic moment the Josephson energies are different for opposite directions of the Néel vector, while these states are degenerate in the absence of the uncompensated moment, for example, for the AB junction

Summary

INTRODUCTION

In the present paper we predict an anomalous ground-state phase shift in a Josephson junction through an antiferromagnet in the presence of Rashba SO coupling. As it was already mentioned above, anomalous phase shifts are considered as key elements in superconducting spintronics. The effect can be relevant to two-dimensional antiferromagnets discovered recently [85,86,87], especially taking into account the large SO coupling predicted for these materials

MODEL AND METHOD

RESULTS

CONCLUSION