This paper proposes an alternative scheme for generating four-photon W state via cavity QED. The scheme bases on the resonant interaction of a A-type three level atom with two bimodal cavities. The detection of atom c...This paper proposes an alternative scheme for generating four-photon W state via cavity QED. The scheme bases on the resonant interaction of a A-type three level atom with two bimodal cavities. The detection of atom collapses the cavity to the desired state. Comparing with previous schemes, the advantage of this scheme is that the interaction time can be greatly shortened since it uses the resonant interaction between atom and cavities. Moreover, the proposed scheme is more experimentally feasible than the previous ones.展开更多
An alternative scheme to approximately conditionally teleport entangled two-mode cavity state without Bell state measurement in cavity QED is proposed. The scheme is based on the resonant interaction of a ladder-type ...An alternative scheme to approximately conditionally teleport entangled two-mode cavity state without Bell state measurement in cavity QED is proposed. The scheme is based on the resonant interaction of a ladder-type three-level atom with two bimodal cavities. The entangled cavity state is reconstructed with only one atom interacting with the two cavities successively.展开更多
A scheme to teleport a superposition of three orthogonal states of an atom without Bell-state measurement in cavity QED is proposed. The scheme based on the resonant interaction of two A-type three-level atoms with a ...A scheme to teleport a superposition of three orthogonal states of an atom without Bell-state measurement in cavity QED is proposed. The scheme based on the resonant interaction of two A-type three-level atoms with a bimodal cavity. The detection of atom ct collapses atom b to the initial state of atom a with cavity mode left in two-mode vacuum state. The probability of success and the fidelity of this scheme are 0.112 and 0.999, respectively.展开更多
We propose a scheme for the generation of entangled states for multiple atoms trapped in three distant cavities connected by two identical single-mode fibers. Compared with the previous schemes, the distinct advantage...We propose a scheme for the generation of entangled states for multiple atoms trapped in three distant cavities connected by two identical single-mode fibers. Compared with the previous schemes, the distinct advantages of the proposed scheme are： First, all the cavities in the proposed protocol can interact with each other freely, which is important in quantum communication and distributed quantum computation. Secondly, in the scheme, the atoms, cavities, and fiber mode are in resonance. Thus, the required interaction time is short, which is important in view of decoherence. In principle, the proposed scheme can be extended to generate n atoms entangled states.展开更多
This paper shows that, based on the single-photon JC model depicting the resonant interaction of a two-level atom with a single cavity mode, an unknown atomic state and cavity photon superposition state can be faithfu...This paper shows that, based on the single-photon JC model depicting the resonant interaction of a two-level atom with a single cavity mode, an unknown atomic state and cavity photon superposition state can be faithfully telcported with only a single measurement. The scheme is probabilistie, its success lies on the event that the sender atom （or the medi-atom, for teleportation of cavity field state） is detected in the higher state. The scheme is in contrast to the previous ones of using a maximally two-particle entangled state as quantum channel.展开更多
The existence of decoherence-free subspace （DFS） has been discussed widely. In this paper, we propose an alternative scheme for generating the four-atom W states by manipulating DF qubits. The atoms are divided into...The existence of decoherence-free subspace （DFS） has been discussed widely. In this paper, we propose an alternative scheme for generating the four-atom W states by manipulating DF qubits. The atoms are divided into two pairs and trapped in two separate optical cavities. Manipulation of atoms within DFS may generate a two-atom maximally entangled state in an individual cavity, which is a stable state. After driving the system out of DFS, the atoms will interact resonantly with the cavity field. The photons leaking from the cavities interfere at the beamsplitter, which destroys which-path information, and are finally detected by one of the detectors, leading to the generation of a W state. In addition, the numerical simulation indicates that the fidelity of the prepared state can, for a very wide parameter regime, be very close to unity.展开更多
We propose a scheme to realize the Heisenberg spin chain in a one-dimensional array of cavities connected by optical fibers.The proposed scheme is based on the off-resonant Raman transitions between two ground states ...We propose a scheme to realize the Heisenberg spin chain in a one-dimensional array of cavities connected by optical fibers.The proposed scheme is based on the off-resonant Raman transitions between two ground states of atoms,and is induced by the cavity modes and external fields.Under the interactions between the nearest neighbors(NNs)and the next NNs,the result shows that the atoms,via the exchange of virtual photons,can be effectively equal to a spin-1/2 Heisenberg model under certain conditions.The parameters of the effective Hamiltonian can be controlled by tuning the laser fields.展开更多
基金supported by National Natural Science Foundation of China (Grant No 10674025)the Development Funds of Fuzhou University of China (Grant No 2007-XY-15)
文摘This paper proposes an alternative scheme for generating four-photon W state via cavity QED. The scheme bases on the resonant interaction of a A-type three level atom with two bimodal cavities. The detection of atom collapses the cavity to the desired state. Comparing with previous schemes, the advantage of this scheme is that the interaction time can be greatly shortened since it uses the resonant interaction between atom and cavities. Moreover, the proposed scheme is more experimentally feasible than the previous ones.
基金supported by the National Natural Science Foundation of China (Grant No 10674025)Funds from Key Laboratory of Quantum Information, University of Science and Technology of Chinathe Department Funds of Fuzhou University of China (Grant No 2007-XY-15)
文摘An alternative scheme to approximately conditionally teleport entangled two-mode cavity state without Bell state measurement in cavity QED is proposed. The scheme is based on the resonant interaction of a ladder-type three-level atom with two bimodal cavities. The entangled cavity state is reconstructed with only one atom interacting with the two cavities successively.
基金Supported by the National Natural Science Foundation of China under Grant No 10674025, and the Fund from Key Lab of Quantum Information at University of Science and Technology of China, and the Development Funds of Fuzhou University under Grant No 2007-XY-15.
文摘A scheme to teleport a superposition of three orthogonal states of an atom without Bell-state measurement in cavity QED is proposed. The scheme based on the resonant interaction of two A-type three-level atoms with a bimodal cavity. The detection of atom ct collapses atom b to the initial state of atom a with cavity mode left in two-mode vacuum state. The probability of success and the fidelity of this scheme are 0.112 and 0.999, respectively.
文摘We propose a scheme for the generation of entangled states for multiple atoms trapped in three distant cavities connected by two identical single-mode fibers. Compared with the previous schemes, the distinct advantages of the proposed scheme are： First, all the cavities in the proposed protocol can interact with each other freely, which is important in quantum communication and distributed quantum computation. Secondly, in the scheme, the atoms, cavities, and fiber mode are in resonance. Thus, the required interaction time is short, which is important in view of decoherence. In principle, the proposed scheme can be extended to generate n atoms entangled states.
基金Project supported by the National Natural Science Foundation of China （Grant No 10674025）, the Key Laboratory of Quantum Information of University of Science and Technology of China, the National Natural Science Foundation of Fujian Province of China （Grant No 2006J0235）, and Foundation of the Education Department of Fujian Province, China （Grant No JB06033）.
文摘This paper shows that, based on the single-photon JC model depicting the resonant interaction of a two-level atom with a single cavity mode, an unknown atomic state and cavity photon superposition state can be faithfully telcported with only a single measurement. The scheme is probabilistie, its success lies on the event that the sender atom （or the medi-atom, for teleportation of cavity field state） is detected in the higher state. The scheme is in contrast to the previous ones of using a maximally two-particle entangled state as quantum channel.
文摘The existence of decoherence-free subspace （DFS） has been discussed widely. In this paper, we propose an alternative scheme for generating the four-atom W states by manipulating DF qubits. The atoms are divided into two pairs and trapped in two separate optical cavities. Manipulation of atoms within DFS may generate a two-atom maximally entangled state in an individual cavity, which is a stable state. After driving the system out of DFS, the atoms will interact resonantly with the cavity field. The photons leaking from the cavities interfere at the beamsplitter, which destroys which-path information, and are finally detected by one of the detectors, leading to the generation of a W state. In addition, the numerical simulation indicates that the fidelity of the prepared state can, for a very wide parameter regime, be very close to unity.
基金Supported by the Natural Science Foundation of Fujian Province under Grant No 2009J06002.
文摘We propose a scheme to realize the Heisenberg spin chain in a one-dimensional array of cavities connected by optical fibers.The proposed scheme is based on the off-resonant Raman transitions between two ground states of atoms,and is induced by the cavity modes and external fields.Under the interactions between the nearest neighbors(NNs)and the next NNs,the result shows that the atoms,via the exchange of virtual photons,can be effectively equal to a spin-1/2 Heisenberg model under certain conditions.The parameters of the effective Hamiltonian can be controlled by tuning the laser fields.
