Phase jumps in Josephson junctions with time-dependent spin-orbit coupling

TL;DR

This paper explores how time-dependent spin-orbit coupling in Josephson junctions enables novel switching mechanisms, phase jumps, and nonreciprocal transport effects, broadening their potential applications in quantum computing and superconducting electronics.

Contribution

It introduces the concept of time-dependent SOC in Josephson junctions, revealing new switching mechanisms and phase dynamics not previously studied.

Findings

Time-dependent SOC induces $2 ext{-} ext{pi}$ phase jumps and voltage pulses.

Anharmonic current-phase relations lead to nonreciprocal transport and diode effects.

Switching mechanisms support fractional-flux-quantum circuits and neuromorphic computing.

Abstract

Planar Josephson junctions (JJs), based on common superconductors and III-V semiconductors, are sought for Majorana states and fault-tolerant quantum computing. However, with gate-tunable spin-orbit coupling (SOC), we show that the range of potential applications of such JJs becomes much broader. The time-dependent SOC offers unexplored mechanisms for switching JJs, accompanied by the $2\pi$-phase jumps and the voltage pulses corresponding to the single-flux-quantum transitions, key to high-speed and low-power superconducting electronics. In a constant applied magnetic field, with Rashba and Dresselhaus SOC, anharmonic current-phase relations, calculated microscopically in these JJs, yield a nonreciprocal transport and superconducting diode effect. Together with the time-dependent SOC, this allows us to identify a switching mechanism at no applied current bias which supports fractional-flux-quantum superconducting circuits and neuromorphic computing.