Resonantly Tunable Majorana Polariton in a Microwave Cavity

We study the spectrum of a one-dimensional Kitaev chain placed in a microwave cavity. In the offresonant 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 is sensitive to the presence of photons in the microwave cavity 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 Majorana polariton. DOI: 10.1103/PhysRevLett.109.257002