Nonreciprocal Josephson current through a conical magnet

TL;DR

This paper proposes a Josephson diode utilizing a single magnetic material with a conical spin structure, leveraging spin-induced band splitting and Zeeman effects to achieve high diode efficiency near the 0-π transition.

Contribution

It introduces a novel Josephson diode design based on conical magnetic materials, combining Rashba-like band splitting and Zeeman effects for enhanced diode performance.

Findings

Achieves large diode efficiency near the 0-π transition.

Demonstrates the role of conical spin structures in Josephson diodes.

Links magnetic spin textures to supercurrent rectification.

Abstract

Superconductors can form ideal diodes carrying nondissipative supercurrents in the forward direction and dissipative currents in the backward direction. The Josephson diode has proven to be a promising design where the junction between the two superconductors comprises the weakest link and thus provides the dominant mechanism. We here propose a Josephson diode based on a single magnetic material with a conical spin structure. The helical spin rotation produces Rashba-like band splitting inversely proportional to the rotation period. Together with the Zeeman splitting caused by the time-reversal symmetry breaking of the noncoplanar spin texture, this results in a large diode efficiency close to the $0-\pi$ transition of the magnetic Josephson junction.