We consider the situation that two atomic ensembles are separately trapped in coupled single-mode cavities, and each atom non-resonantly interacts with cavity field via a one-photon hopping. By employing the negativity measure of entanglement, we investigate the temporal evolution of entanglements between the cavities as well as between the cavity and atomic ensemble. By means of the numerical calculations, we discuss the influences of the number of atoms in an atomic ensemble and the detuning on the entanglement. The results show that as the number of atoms increases, the entanglement between the cavities is strengthened, contrary the entanglement between atomic ensemble and cavity is weakened. On the other hand, as the detuning increases, the entanglement between the cavities is weakened, contrary the entanglement between atomic ensemble and cavity is strengthened.
We propose a scheme for realizing the Kerr-type nonlinearity for a cavity mode. In the scheme the cavity mode interacts with a single three-level atom dispersively. Under certain conditions, the evolution of the cavity field, decoupled from the atomic degree of freedom, corresponds to the Kerr effect. The scheme can be generalized to implement cross-Kerr effect and two-qubit phase gates for two cavity modes. 相似文献
We study the entanglement evolution between two atoms, which are initially entangled with a third atom and trapped in two
separated cavities coupled by an optical fiber. We also investigate the temporal evolution in the entanglement between the
atom and the local cavity mode. The influence of the state-selective measurement on the atom outside the cavities and the
influence of cavity-fiber coupling coefficient on the entanglement are discussed. The results show that the entanglement can
be strengthened through the state-selective measurement on the atom outside the cavities. We also find that, by increasing
the cavity-fiber coupling coefficient, the atom-atom entanglement is strengthened, but the atom-cavity entanglement is weakened. 相似文献