Diode effect in a skyrmion-coupled high-temperature Josephson junction

TL;DR

This paper demonstrates a tunable superconducting diode effect in a $d$-wave Josephson junction influenced by a skyrmion crystal, enabling high-temperature operation and control via external parameters.

Contribution

It introduces a novel mechanism for a gate-tunable superconducting diode using skyrmion-induced symmetry breaking in high-$T_c$ superconductor junctions.

Findings

Diode efficiency is tunable by gate voltage and skyrmion size.

The effect persists at higher temperatures with $d$-wave superconductors.

Theoretical models confirm the asymmetric current-phase relation.

Abstract

We show that a planar Josephson junction having $d$-wave superconducting regions, with a skyrmion crystal placed underneath, produces a robust gate-tunable superconducting diode effect. The spatially-varying exchange field of the skyrmion crystal breaks both inversion and time-reversal symmetries, leading to an asymmetric current-phase relation with an anomalous phase shift. Our theoretical calculations, obtained using resistively and capacitively shunted junction model combined with Bogoliubov-de Gennes method, reveal that the diode efficiency is largely tunable by controlling external gate voltage and skyrmion radius. Incorporation of a $d$-wave superconductor such as high-$T_c$ Cuprate enables the diode to function at higher operating temperatures. Our results establish a unique and practically-realizable mechanism for devising tunable field-free superconducting diodes based on magnetic texture-superconductor hybrid platforms.