Bichromatically-controlled entanglement between asymmetric quantum dots in a photonic cavity

Abstract

Entanglement generation and control of two spatially separated asymmetric quantum dots with broken inversion symmetry and mediated by a photonic cavity is studied using a quantum master equation formalism. The quantum dots are coherently driven by a bichromatic laser consisting of a strong optical field nearly resonant with the optical transition of each quantum dot, and a low frequency field. The optical field dresses each quantum dot, and due to the presence of large permanent dipole moments in the quantum dots they are coupled by the low frequency field. We make use of the generated dressed-state scheme for entanglement control. The master equation which describes the interaction with the cavity modes and the coherent fields is numerically solved. In order to gain some insight on the role of the external parameters on entanglement, an effective Hamiltonian for the atomic subsystem is derived in the dressed state representation by adiabatically eliminating the cavity field operators. It is found that steady-state entanglement can be controlled by means of the amplitude and frequency of the low frequency field.