Cavity superconductor-polaritons

TL;DR

This paper explores the hybridization of cavity photons with Bardasis-Schrieffer modes in superconductors, leading to novel polariton states that could induce a mixed superconducting order parameter.

Contribution

It introduces a method to engineer coupling between cavity photons and BS modes via supercurrent, resulting in hybridized states with potential to alter superconducting symmetry.

Findings

Hybridized Bardasis-Schrieffer-polariton states are theoretically obtained.

These states have overlap with photon and d-wave superconducting fluctuations.

Condensation of these states could produce an $s extpm id$ superconducting phase.

Abstract

Following the recent success of realizing exciton-polariton condensates in cavities, we examine the hybridization of cavity photons with the closest analog of excitons within a superconductor, states called Bardasis-Schrieffer (BS) modes. Though BS modes do not typically couple directly to light, one can engineer a coupling with an externally imposed supercurrent, leading to the formation of hybridized Bardasis-Schrieffer-polariton states, which we obtain both via direct solution and through the derivation of an effective Hamiltonian picture for the model. These new excitations have nontrivial overlap with both the original photon states and $d$-wave superconducting fluctuations, implying that their condensation could produce a finite $d$-wave component of the superconducting order parameter--an $s\pm id$ superconducting state.