Exceptional points in a time-periodic parity-time-symmetric Rabi model

Abstract

We investigate the effect of a periodic modulation on parity-time symmetry in a non-Hermitian Rabi model with balanced gain or loss. It is shown that under the multiple-photon resonance conditions, this Rabi model supports exact Floquet solutions for certain special parameter conditions which allow us to find exact analytical results for the position of certain exceptional points (EPs). It is also found numerically that there exists a universal relation between the number of the EPs and the gain or loss strength.