# Dynamical Casimir effect via four- and five-photon transitions using a strongly detuned atom

## TL;DR

This paper explores multi-photon dynamical Casimir effects in a modulated cavity with detuned qubits or cyclic qutrits, revealing peaks in photon generation rates for specific multi-photon transitions and providing analytical and numerical insights.

## Contribution

It introduces a detailed analytical and numerical study of four- and five-photon transitions in a modulated cavity with strongly detuned quantum systems, highlighting new multi-photon dynamical Casimir effects.

## Key findings

- Photon generation peaks at specific modulation frequencies for four- and five-photon processes.
- Analytical solutions for the unitary evolution of the system.
- Feasibility of observing multi-photon dynamical Casimir effect with weak dissipation.

## Abstract

The scenario of a single-mode cavity with harmonically modulated frequency is revisited in the presence of strongly detuned qubit or cyclic qutrit. It is found that when the qubit frequency is close to $3\nu $ there is a peak in the photon generation rate via four-photon transitions for the modulation frequency $4\nu $, where $\nu $ is the average cavity frequency. Effective five-photon processes can occur for the modulation frequency $5\nu $ in the presence of a cyclic qutrit, and the corresponding transition rates exhibit series of peaks. Closed analytical description is derived for the unitary evolution, and numeric simulations indicate the feasibility of multi-photon dynamical Casimir effect under weak dissipation.