Homointerface planar Josephson junction based on inverse proximity effect

TL;DR

This paper presents a novel fabrication technique for planar Josephson junctions with perfect superconductor-normal metal interfaces, leveraging a strong inverse proximity effect in Al/V$_5$S$_8$ bilayers to achieve high transparency and enhanced supercurrent flow.

Contribution

The work introduces a new method to create highly transparent S/N interfaces in Josephson junctions using inverse proximity effect in Al/V$_5$S$_8$ bilayers, enabling improved supercurrent performance.

Findings

Achieved a supercurrent flow across a 2.9 μm weak link.

Demonstrated a giant critical current and large I_c R_N product.

Utilized inverse proximity effect to enhance interface transparency.

Abstract

The quality of a superconductor-normal metal-superconductor Josephson junction (JJ) depends crucially on the transparency of the superconductor-normal metal (S/N) interface. We demonstrate a technique for fabricating planar JJs with perfect S/N interfaces. The technique utilizes a strong inverse proximity effect discovered in Al/V$_5$S$_8$ bilayers, by which the Al layer is driven into the resistive state. The highly transparent S/N homointerface and the peculiar normal metal enable the flow of Josephson supercurrent across a 2.9 $\mu$m long weak link. Moreover, our JJ exhibits a giant critical current and a large product of the critical current and the normal state resistance.