Blockade and Counterflow Supercurrent in exciton-condensate Josephson junctions

TL;DR

This paper introduces a new Andreev-like scattering mechanism enabling perfect conversion between charged and neutral supercurrents in exciton-condensate Josephson junctions, significantly affecting superflow behavior.

Contribution

It presents a novel mechanism for supercurrent conversion and demonstrates its impact on superflow control in coupled superconducting bilayer systems.

Findings

Supercurrents can be perfectly converted between charged and neutral forms.

Superflow can be completely blocked or exhibit perfect drag depending on phase biases.

The mechanism enables new ways to control supercurrents in hybrid systems.

Abstract

We demonstrate that perfect conversion between charged supercurrents in superconductors and neutral supercurrents in electron-hole pair condensates is possible via a new Andreev-like scattering mechanism. As a result, when two superconducting circuits are coupled through a bilayer exciton condensate, the superflow in both layers is drastically modified. Depending on the phase biases the supercurrents can be completely blocked or exhibit perfect drag.