Demonstration of a superconducting diode-with-memory, operational at zero magnetic field with switchable nonreciprocity

TL;DR

This paper presents superconducting diodes that operate at zero magnetic field, with switchable nonreciprocity and memory capabilities, based on niobium Josephson junctions influenced by self-field effects and trapped vortices.

Contribution

It introduces a superconducting diode with switchable nonreciprocity and memory functionality, operating at zero magnetic field using conventional Josephson junctions.

Findings

Nonreciprocity of critical current can reach an order of magnitude.

Rectification efficiency exceeds 70%.

Diode polarity and nonreciprocity can be switched on/off.

Abstract

Diode is one of basic electronic components. It has a nonreciprocal current response, associated with a broken space/time reversal symmetry. Here we demonstrate prototypes of superconducting diodes operational at zero magnetic field. They are based on conventional niobium planar Josephson junctions, in which space/time symmetry is broken by a combination of self-field effect from nonuniform bias and stray fields from a trapped Abrikosov vortex. We demonstrate that nonreciprocity of critical current in such diodes can reach an order of magnitude and rectification efficiency can exceed 70$\%$. Furthermore, we can easily change the diode polarity and switch nonreciprocity on/off by changing bias configuration and by trapping/removing a vortex. This facilitates memory functionality. We argue that such diode-with-memory can be used for a future generation of in-memory superconducting computers.