Decoherence attenuation in the Tavis-Cummings model via transition frequency modulation with dipole–dipole interaction and multi-photon transitions

Abstract

Producing and protecting the coherence and entanglement is of practical importance in quantum information processing and technologies. In this paper, using the Tavis-Cummings model we investigate the interaction between two two-level atoms with a reservoir via applying qubit transition frequency modulation and considering dipole–dipole interaction and multi-photon transitions in the Markovian and non-Markovian regimes. After introducing the model as well as its proper Hamiltonian, via the time-dependent Schrödinger equation we obtain the probability amplitudes of the system state vector, by which we analyze the coherence properties by considering different involved parameters. Generally, it will be observed that transition frequency modulation prevents the attenuation of coherence of two-qubit system. In particular, we find that, in the non-Markovian regime, by applying the frequency modulation in a certain range of dipole–dipole interaction strength, the amount of coherence is reduced; however, by increasing the dipole–dipole coupling, the degree of coherence is increased. Also, for single- and two-photon transitions, comparing with four-photon case, decoherence occurs in longer times.