Transverse Josephson diode effect in tilted Dirac systems

TL;DR

This paper predicts a transverse Josephson diode effect in tilted Dirac systems, where a phase-driven transverse current exhibits diode-like asymmetry, enabling nonreciprocal superconducting device applications.

Contribution

It introduces the concept of a transverse Josephson diode effect in tilted Dirac materials with valley-dependent gaps, a novel phenomenon not previously reported.

Findings

Finite tilt-assisted transverse Josephson Hall current exists under broken time-reversal symmetry.

The transverse current shows a nonsinusoidal current-phase relation.

The effect supports a fully polarized diode efficiency with 100% quality factor.

Abstract

We theoretically study the transverse charge transport in Josephson junctions based on the tilted Dirac materials with valley-dependent gaps. It is shown that a finite tilt-assisted transverse Josephson Hall current is present under broken time-reversal symmetry. This transverse current is driven by the superconducting phase difference across the junction and exhibits a nonsinusoidal current-phase relation, leading to the transverse Josephson diode effect (TJDE), where the critical currents flowing oppositely along the transverse direction are asymmetric. Compared to the conventional longitudinal Josephson diode effect, the predicted TJDE supports a fully polarized diode efficiency with a $100\%$ quality factor and can completely decouple the input signal path from the output, suggesting potential applications for nonreciprocal superconducting devices.