Floquet engineering the quantum Rabi model in the ultrastrong coupling regime

TL;DR

This paper explores how periodic modulation of the cavity-dipole coupling in the quantum Rabi model can generate rich Floquet states and produce real photons through mechanical driving in the ultrastrong coupling regime.

Contribution

It introduces a method to engineer Floquet states in the quantum Rabi model via periodic coupling modulation, enabling photon generation through mechanical driving.

Findings

Periodic modulation leads to complex Floquet states.

Mechanical driving can produce real photons.

Photon generation depends on modulation strength and frequency.

Abstract

We study the quantum Rabi model for a two-level system coupled to a quantized cavity mode under periodic modulation of the cavity-dipole coupling in the ultrastrong coupling regime, leading to rich Floquet states. As an application of the theory, we show how purely mechanical driving can produce real photons, depending on the strength and frequency of the periodic coupling rate.