Photogalvanic phenomena in superconductors supporting intrinsic diode effect

TL;DR

This paper develops a phenomenological theory explaining how photogalvanic effects in superconductors can induce a diode effect, leading to controllable supercurrents and vortex state switching via electromagnetic waves.

Contribution

It introduces a generalized London model incorporating quadratic nonlinearity to describe photogalvanic phenomena and the resulting superconducting phase differences and supercurrents.

Findings

Electromagnetic waves can generate a superconducting phase difference.

Phase differences can induce circulating supercurrents in a loop.

Increasing wave intensity can switch vortex states.

Abstract

In this work we suggest a phenomenological theory of photogalvanic phenomena in superconducting materials and structures revealing the diode effect. Starting from a generalized London model including the quadratic nonlinearity in the relation between the supercurrent and superfluid velocity we show that the electromagnetic wave incident on the superconductor can generate a nontrivial superconducting phase difference between the ends of the sample. Being enclosed in a superconducting loop such phase battery should generate a dc supercurrent circulating in the loop. Increasing the electromagnetic wave intensity one can provoke the switching between the loop states with different vorticities.