Effect of Quasiparticles Injection on the AC Response of a Superconductor

TL;DR

This paper investigates how injecting quasiparticles into a superconductor affects its AC response, revealing that the dissipative response increases significantly with quasiparticle injection, regardless of electron-hole imbalance.

Contribution

It provides a theoretical calculation of the AC linear response of a superconductor under nonequilibrium conditions caused by quasiparticle injection.

Findings

Dissipative response increases with quasiparticle number.

Response is proportional to total quasiparticles, independent of electron-hole imbalance.

Injection from normal leads significantly alters superconductor's AC behavior.

Abstract

We calculate the AC linear response of a superconductor in a nonequilibrium electronic state. The nonequilibrium state is produced by injecting quasiparticles into the superconductor from normal leads through asymmetric tunnel contacts. The dissipative part of the response is drastically increased by the injected quasiparticles and is proportional to their total number regardless of the imbalance between the numbers of electron-like and hole-like excitations.