Nonvolatile electric switching of critical current in cross-bar superconducting junctions

TL;DR

This paper demonstrates a nonvolatile, electrically switchable critical current in superconducting junctions, enabling scalable, low-power superconducting electronics with unique vortex-based behaviors.

Contribution

It introduces a novel method for deterministic nonvolatile electrical switching of critical current in superconducting junctions, with insights into vortex dynamics and potential for integrated circuits.

Findings

Critical current modulated by a factor of four with 60% efficiency.

Achieved switching at a reduced current density of 5×10^5 A/cm².

Observed electrically switchable critical temperature and non-monotonic I_c-H_z response.

Abstract

Superconducting (SC) diodes are key passive building blocks for future SC electronics. However, realizing their active counterparts is essential for functional logic. Here, we demonstrate deterministic nonvolatile electrical switching of the critical current ($I_\text{c}$) in overlap crossbar SC junctions. By applying a minimal perpendicular magnetic field ($H_\text{z}$), $I_\text{c}$ is modulated by a factor of four with a large switching efficiency of 60\%, achieved at a significantly reduced excitation current density of $5\times10^5$~A/cm$^2$. We also uncover anomalous behaviors: an electrically switchable critical temperature and a non-monotonic $I_\text{c}$-$H_\textit{z}$ response. These observations are interpreted in terms of unique asymmetry involving isolated vortex injection, configuration and repulsion inherent to the junction geometry. Our device provides a scalable, low-power alternative to complex SQUID-based architectures, paving the way for high-density SC integrated circuits.