Geometric quantum discord and entanglement between two atoms in Tavis-Cummings model with dipole-dipole interaction under intrinsic decoherence

Abstract

Quantum correlation and entanglement, measured by geometric quantum discord (GQD) and concurrence respectively, between two identical two-level atoms are investigated in detail in Tavis-Cummings model with dipole-dipole interaction (DDI) under intrinsic decoherence. The results show that the phase decoherence rate makes the original harmonic vibration with respective to time decay to a stable value. DDI coupling enhances GQD and corcurrence and even avoids entanglement sudden death (ESD). By the introduction of phase decoherence rate, the atom-light field coupling coefficient makes the decay of periodical curves quicker. Evolution periods are shortened as photon number increases, as well DDI and atomic-light field coupling become stronger. Moreover, both GQD and concurrence have nothing to do with frequency of cavity field and atoms for the resonant case.