Hybrid light-matter states in topological superconductors coupled to cavity photons

TL;DR

This paper explores the formation of polaritons in a topological superconductor coupled to a cavity, revealing how Majorana states influence the hybrid light-matter spectrum and could serve as signatures of topological phases.

Contribution

It demonstrates the emergence of polaritons in topological superconductors and shows their sensitivity to Majorana states and parity, advancing understanding of light-matter interactions in topological systems.

Findings

Lower polariton modes in the topological phase involve Majorana transitions.

Polariton spectra are sensitive to Majorana parity.

Distinct polariton features differentiate topological from trivial phases.

Abstract

We consider a one-dimensional topological superconductor hosting Majorana bound states at its ends coupled to a single mode cavity. In the strong light-matter coupling regime, electronic and photonic degrees of freedom hybridize resulting in the formation of polaritons. We find the polariton spectrum by calculating the cavity photon spectral function of the coupled electron-photon system. In the topological phase the lower in energy polariton modes are formed by the bulk-Majorana transitions coupled to cavity photons and are also sensitive to the Majorana parity. In the trivial phase the lower polariton modes emerge due to the coupling of the bulk-bulk transitions across the gap to photons. Our work demonstrates the formation of polaritons in topological superconductors coupled to photons that contain information on the features of the Majorana bound states.