Electromagnetic response of a static vortex line in a type-II superconductor : a microscopic study

TL;DR

This paper investigates the electromagnetic response of a pinned vortex in a type-II superconductor using a microscopic Bogoliubov-de Gennes approach, revealing asymmetries and nonreciprocal effects in light interactions.

Contribution

It provides a detailed microscopic analysis of vortex electromagnetic responses, including selection rules and asymmetries, which were not previously characterized.

Findings

Light absorption depends on the handedness of incident radiation.

Predicted nonreciprocal circular birefringence effects.

Identified structure in frequency-dependent conductivity and Raman scattering cross section.

Abstract

The electromagnetic response of a pinned Abrikosov fluxoid is examined in the framework of the Bogoliubov-de Gennes formalism. The matrix elements and the selection rules for both the single photon (emission - absorption) and two photon (Raman scattering) processes are obtained. The results reveal striking asymmetries: light absorption by quasiparticle pair creation or single quasiparticle scattering can occur only if the handedness of the incident radiation is opposite to that of the vortex core states. We show how these effects will lead to nonreciprocal circular birefringence, and also predict structure in the frequency dependence of conductivity and in the differential cross section of the Raman scattering.