Photoinduced Anomalous Supercurrent Hall Effect

TL;DR

This paper predicts a novel photoinduced Hall effect in 2D superconductors with supercurrent under circularly polarized light, involving a transverse supercurrent due to quasiparticle dynamics and symmetry breaking.

Contribution

It introduces a microscopic theory for a photoinduced supercurrent Hall effect in superconductors, highlighting the role of light frequency, disorder, and quasiparticle recombination.

Findings

Hall supercurrent proportional to quasiparticle recombination time

Effect occurs when light frequency exceeds twice the superconducting gap

Disorder breaks Galilean invariance, enabling the effect

Abstract

We predict a photoinduced Hall effect in an isotropic conventional two-dimensional superconductor with a built-in supercurrent exposed to a circularly-polarized light. This second-order with respect to the electromagnetic field amplitude effect occurs when the frequency of the field exceeds the double value of the superconducting gap. It reveals itself in the emergence of a Cooper-pair condensate flow in the direction transverse to the initial built-in supercurrent, which arises to compensate for the light-induced electric current of quasiparticles photoexcited across the gap. The initial supercurrent breaks both the time-reversal and inversion symmetries, while the presence of dilute disorder in the sample provides the breaking of the Galilean invariance. We develop a microscopic theory of the supercurrent Hall effect in the case of weak disorder and show, that the Hall supercurrent is directly proportional to the quasiparticle recombination time, which can acquire large values.