Resonantly Tunable Majorana Polariton in a Microwave Cavity

TL;DR

This paper explores how a microwave cavity can control and detect topological phases in a Kitaev chain, revealing a new Majorana polariton state in the resonant regime with potential quantum information applications.

Contribution

It introduces the concept of Majorana polaritons formed by coupling a Kitaev chain to a microwave cavity, demonstrating control over topological phases via cavity occupation.

Findings

Cavity frequency shift signals topological phase transition.

Resonant regime enables cavity-controlled topological states.

Existence of a degenerate Majorana polariton subspace.

Abstract

We study the spectrum of a one-dimensional Kitaev chain placed in a microwave cavity. In the off-resonant regime, the frequency shift of the cavity can be used to identify the topological phase transition of the coupled system. In the resonant regime, the topology of the system can be controlled via the microwave cavity occupation and, moreover, for a large number of photons (classical limit), the physics becomes similar to that of periodically-driven systems (Floquet insulators). We also analyze numerically a finite chain and show the existence of a degenerate subspace in the presence of the cavity that can be interpreted as a \textit{Majorana polariton}.