We present a physical scheme for realizing probabilistic teleportation of bipartite atomic states via cavity QED. This scheme requires only a nonmaximally entangled pair used as quantum channel, so we reduce the requi...We present a physical scheme for realizing probabilistic teleportation of bipartite atomic states via cavity QED. This scheme requires only a nonmaximally entangled pair used as quantum channel, so we reduce the requirement of entanglement.展开更多
We study that two atoms simultaneously interact with a single mode thermal field via different couplings and different spontaneous emission rates when two-photon process is involved. It is found that we indeed can emp...We study that two atoms simultaneously interact with a single mode thermal field via different couplings and different spontaneous emission rates when two-photon process is involved. It is found that we indeed can employ the different couplings to produce the two-atom thermal entanglement in two-photon process. The different atomic spontaneous emission rates are also utilizable in generating thermal entanglement. We also investigate the effect of the can obtain a strong and steady entanglement.展开更多
We have proposed an alternative scheme for teleportation of two-atom entangled state in cavity QED. It is based on the degenerate Raman interaction of a single-mode cavity field with a A-type three-level atom. The pro...We have proposed an alternative scheme for teleportation of two-atom entangled state in cavity QED. It is based on the degenerate Raman interaction of a single-mode cavity field with a A-type three-level atom. The prominent feature of the scheme is that only one cavity is required, which is prior to the previous one. Moreover, the atoms need to be detected are reduced compared with the previous scheme. The experimental feasibility of the scheme is discussed. The scheme can easily be generalized for teleportation of N-atom GHZ entangled states. The number of the atoms needed to be detected does not increase as the number of the atoms in GHZ state increases.展开更多
We study a special two-atom entanglement case in assumed cavity QED experiment in which only one atom effectively exchanges a single photon with a cavity mode. We compute two-atom entanglement under position-dependent...We study a special two-atom entanglement case in assumed cavity QED experiment in which only one atom effectively exchanges a single photon with a cavity mode. We compute two-atom entanglement under position-dependent atomic resonant dipole-dipole interaction （RDDI） for large interatomic separation limit. We show that the RDDI, even t, hat which is much smaller than the maximal atomic Rabi frequency, can induce distinct diatom entanglement. The peak entanglement reaches a maximum when RDDI strength can compare with the Rabi frequency of an atom.展开更多
We present a scheme using four two-level atoms and a bimodal cavity to get approximate conditional teleportation of an arbitrary entangled atomic state without using the Bell-state measurement.
Considering the intrinsic decoherence proposed by Milburn, we investigate the entanglement between two two-level atoms induced by a Fock state of single-mode quantized radiation field. The time-dependent reduced densi...Considering the intrinsic decoherence proposed by Milburn, we investigate the entanglement between two two-level atoms induced by a Fock state of single-mode quantized radiation field. The time-dependent reduced density matrix of the atoms system is given explicitly, Due to the intrinsic decoheronce, the atoms system will approach a stationary state, where the stationary entanglement depends on the initial states of the field and the atoms.展开更多
In this paper, we investigate the evolution of two non-identical two-level atoms in two-mode cavity fields. We demonstrate the death and rebirth effect of entanglement for two non-identical two-level atoms under some ...In this paper, we investigate the evolution of two non-identical two-level atoms in two-mode cavity fields. We demonstrate the death and rebirth effect of entanglement for two non-identical two-level atoms under some initial conditions. It is also exemplified that entangled states of two nonidentical two-level atoms can be generated by entangled two-mode cavity fields. This research can be considered as a first step to further investigate the problem of manipulating two nonidentical two-level atoms in two-mode cavity fields.展开更多
We study the normal form of multipartite density matrices.It is shown that the correlation matrix(CM)separability criterion can be improved from the normal form we obtained under filtering transformations.Based on CMc...We study the normal form of multipartite density matrices.It is shown that the correlation matrix(CM)separability criterion can be improved from the normal form we obtained under filtering transformations.Based on CMcriterion the entanglement witness is further constructed in terms of local orthogonal observables for both bipartite andmultipartite systems.展开更多
Negativity has been adopted to investigate the entanglement in a system composed of a two-level atom anda two-mode cavity field.Effects of Kerr-like medium and the number of photon inside the cavity on the entanglemen...Negativity has been adopted to investigate the entanglement in a system composed of a two-level atom anda two-mode cavity field.Effects of Kerr-like medium and the number of photon inside the cavity on the entanglementare studied.Our results show that atomic initial state must be superposed,so that the two cavity field modes can beentangled.Moreover,we also conclude that the number of photon in the two cavity mode should be equal.The interactionbetween modes,namely,the Kerr effect,has a significant negative contribution.Note that the atom frequency and thecavity frequency have an indistinguishable effect,so a corresponding approximation has been made in this article.Theseresults may be useful for quantum information in optics systems.展开更多
基金The project supported by the Natural Science Foundation of the Education Department of Anhui Province of China under Grant No. 2004kj005zd and Natural Science Foundation of Anhui Province of China under Grant No. 03042401, and the Talent Foundation of Anhui University
文摘We present a physical scheme for realizing probabilistic teleportation of bipartite atomic states via cavity QED. This scheme requires only a nonmaximally entangled pair used as quantum channel, so we reduce the requirement of entanglement.
文摘We study that two atoms simultaneously interact with a single mode thermal field via different couplings and different spontaneous emission rates when two-photon process is involved. It is found that we indeed can employ the different couplings to produce the two-atom thermal entanglement in two-photon process. The different atomic spontaneous emission rates are also utilizable in generating thermal entanglement. We also investigate the effect of the can obtain a strong and steady entanglement.
基金The project supported by the National Natural Science Foundation of China under Grant No. 10225421
文摘We have proposed an alternative scheme for teleportation of two-atom entangled state in cavity QED. It is based on the degenerate Raman interaction of a single-mode cavity field with a A-type three-level atom. The prominent feature of the scheme is that only one cavity is required, which is prior to the previous one. Moreover, the atoms need to be detected are reduced compared with the previous scheme. The experimental feasibility of the scheme is discussed. The scheme can easily be generalized for teleportation of N-atom GHZ entangled states. The number of the atoms needed to be detected does not increase as the number of the atoms in GHZ state increases.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10347103, 10305002, and 60472017
文摘We study a special two-atom entanglement case in assumed cavity QED experiment in which only one atom effectively exchanges a single photon with a cavity mode. We compute two-atom entanglement under position-dependent atomic resonant dipole-dipole interaction （RDDI） for large interatomic separation limit. We show that the RDDI, even t, hat which is much smaller than the maximal atomic Rabi frequency, can induce distinct diatom entanglement. The peak entanglement reaches a maximum when RDDI strength can compare with the Rabi frequency of an atom.
文摘We present a scheme using four two-level atoms and a bimodal cavity to get approximate conditional teleportation of an arbitrary entangled atomic state without using the Bell-state measurement.
基金The project supported by National Natural Science Foundation of China under Grant No, 10374007
文摘Considering the intrinsic decoherence proposed by Milburn, we investigate the entanglement between two two-level atoms induced by a Fock state of single-mode quantized radiation field. The time-dependent reduced density matrix of the atoms system is given explicitly, Due to the intrinsic decoheronce, the atoms system will approach a stationary state, where the stationary entanglement depends on the initial states of the field and the atoms.
基金supported by the National Natural Science Foundation of China under Grant Nos.60674040 and 60774099partly supported by the Key Laboratory of Systems and Control,Chinese Academy of Sciences
文摘In this paper, we investigate the evolution of two non-identical two-level atoms in two-mode cavity fields. We demonstrate the death and rebirth effect of entanglement for two non-identical two-level atoms under some initial conditions. It is also exemplified that entangled states of two nonidentical two-level atoms can be generated by entangled two-mode cavity fields. This research can be considered as a first step to further investigate the problem of manipulating two nonidentical two-level atoms in two-mode cavity fields.
基金National Natural Science Foundation of China under Grant Nos.10675086 and KM200510028022National Key Basic Research Program of China under Grant No.2004CB318000
文摘We study the normal form of multipartite density matrices.It is shown that the correlation matrix(CM)separability criterion can be improved from the normal form we obtained under filtering transformations.Based on CMcriterion the entanglement witness is further constructed in terms of local orthogonal observables for both bipartite andmultipartite systems.
基金Supported by National Natural Science Foundation of China under Grant Nos.10604053,2006CB932603,and 90305026Beihang Lantian Project
文摘Negativity has been adopted to investigate the entanglement in a system composed of a two-level atom anda two-mode cavity field.Effects of Kerr-like medium and the number of photon inside the cavity on the entanglementare studied.Our results show that atomic initial state must be superposed,so that the two cavity field modes can beentangled.Moreover,we also conclude that the number of photon in the two cavity mode should be equal.The interactionbetween modes,namely,the Kerr effect,has a significant negative contribution.Note that the atom frequency and thecavity frequency have an indistinguishable effect,so a corresponding approximation has been made in this article.Theseresults may be useful for quantum information in optics systems.
