Enhanced superconducting diode effect in hybrid Josephson junctions

TL;DR

This paper demonstrates an enhanced superconducting diode effect in hybrid Josephson junctions with patterned hole arrays, showing improved nonreciprocal transport by tuning the transparency difference between bands.

Contribution

It introduces a method to amplify the superconducting diode effect using patterned hole arrays and gate control in InAs-based Josephson junctions, advancing nonreciprocal superconducting device engineering.

Findings

Enhanced diode effect observed with hole array patterning.

Gate depletion increases nonreciprocity without suppressing supercurrent.

Theoretical analysis links transparency differences to the diode effect.

Abstract

The superconducting diode effect (SDE) has recently been observed in various systems, sparking interest in novel superconducting devices and offering a new platform to probe intrinsic material properties. Josephson junctions with strong Rashba spin-orbit coupling have exhibited nonreciprocal critical currents under applied magnetic fields. In this work, we investigate the SDE in Josephson junctions incorporating periodic hole arrays patterned into the superconducting leads on InAs heterostructures with epitaxial aluminum. We observe an enhanced diode effect when a top gate depletes the 2DEG in the region of the hole arrays, while preserving the overall supercurrent. Theoretical analysis shows that the physics behind this phenomenon is the increased difference of transparency between different bands in the junction. These results highlight a new pathway for engineering and controlling nonreciprocal superconducting transport in hybrid systems.