Probabilistic Teleportation of an Arbitrary Two-mode <Emphasis Type="Italic">N</Emphasis>-photon Entangled State in Cavity QED

We propose a scheme for teleportation of an arbitrary two-mode N-photon entangled states in cavity QED. The scheme is based on the resonant interaction between Λ-type atoms and two-mode cavity fields. In contrast to all the theoretical schemes proposed previously in cavity QED for teleportation of two-mode cavity field states, in the present scheme, the established entanglement for the quantum channel is the type of the multi-dimensional entanglement between the symmetric multi-atom Dicke states and two-mode N-photon states. Therefore, the scheme extends the scope of the theoretical study of the teleportation.     

Scheme for Implementation of Quantum Game in Cavity QED

We propose an experimentally feasible scheme to implement two-player quantum game in cavity quantum electrodynamics （QED）. During the process, the cavity is only virtually excited, thus our scheme is insensitive to the cavity field states and cavity decay. The scheme can be realized in the range of current cavity QED techniques.     

Efficient scheme for two-atom entanglement and quantum information processing in cavity QED

A scheme is proposed for the generation of two-atom maximally entangled states and realization of quantum logic gates and teleportation with cavity QED. The scheme does not require the transfer of quantum information between the atoms and cavity. In the scheme the cavity is only virtually excited and thus the requirement on the quality factor of the cavities is greatly loosened.     

A scheme for implementing quantum game in cavity QED

In this paper, we propose a scheme for implementing quantum game (QG) in cavity quantum electrodynamics(QED). In the scheme, the cavity is only virtually excited and thus the proposal is insensitive to the cavity fields states and cavity decay. So our proposal can be experimentally realized in the range of current cavity QED techniques.     

Quantum Dense Coding Based on Entangled Bell State in Cavity QED

We investigate quantum dense coding based on entangled Bell states in cavity QED. We implement a experimentally feasible new scheme in cavity QED with atomic qubits where the atoms interact with a highly detuned cavity mode with the assistance of a classical field. The scheme is insensitive to the cavity decay and the thermal field. Based on cavity QED techniques, the scheme can be realizable.     

Revisiting “Quantum State Sharing of an Arbitrary Two-Atom State by Using a Six-Atom Cluster State in Cavity QED”

In Nie et al. (Int. J. Theor. Phys. 50: 2526, 2011), authors put forward a cavity QED scheme for deterministic quantum state sharing (QSTS) of an arbitrary two-atom state. They claimed that, the quantum channel of the QSTS scheme is a six-atom cluster state. After simple calculation, one can see that the quantum channel they used is a direct product of two three-atom GHZ states. In this paper, we propose a cavity QED scheme for QSTS of an arbitrary two-atom state via a six-atom cluster state channel. In our scheme, two two-atom Bell state measurements are transformed into the discrimination of single-atom product states. Moreover, the two-atom unitary operation is changed to single-qubit unitary operations. Our scheme is insensitive to the cavity decay. The necessary time for the scheme is much shorter than the Rydberg-atom lifespan, therefore atom decays do not need to be considered.     

Quantum computation based on a quantum switch in cavity QED

A feasible scheme for constructing quantum logic gates is proposed on the basis of quantum switches in cavity QED. It is shown that the light field which is fed into the cavity due to the passage of an atom in a certain state can be used to manipulate the conditioned quantum logical gate. In our scheme, the quantum information is encoded in the states of Rydberg atoms and the cavity mode is not used as logical qubits or as a communicating “bus”; thus, the effect of atomic spontaneous emission can be neglected and the strict requirements for the cavity can be relaxed.     

Scheme to implement optimal asymmetric economical 1→3 phase-covariant telecloning via cavity QED

<正>We propose an experimentally feasible scheme to implement the optimal asymmetric economical 1→3 phase-covariant telecloning protocol,which works without ancilla,based on cavity quantum electrodynamics(QED).The scheme is insensitive to the cavity field states and the cavity decay.In the telecloning process,the cavity is only virtually excited,it greatly prolongs the efficient decoherent time.Therefore,the scheme may be experimentally realized in the field of current cavity QED techniques.     

A Scheme for Generating Entangled Squeezed States Based on Cavity QED

We propose a scheme for generating entangled squeezed vacuum states of electromagnetical fields. The scheme is based on cavity QED. In this scheme, an atom interacts, successively, with a classical field, two quantum cavity fields, and another classical field. By detecting the final states of the atom, the two quantum cavity fields will be projected to an entangled state.     

A proposal to implement a quantum delayed choice experiment assisted by cavity QED

We propose a scheme with current technology to implement a quantum delayed-choice experiment in the realm of cavity QED. Our scheme uses two-level atoms interacting on and off resonantly with a single mode of a high Q cavity. At the end of the protocol, the state of the cavity returns to its ground state, allowing new sequential operations. The particle and wave behavior, which are verified in a single experimental setup, are postselected after the atomic states are selectively detected.     

An Alternative Scheme for Transferring Quantum States and Preparing a Quantum Network in Cavity QED

An alternative scheme is proposed to transfer quantum states and prepare a quantum network in cavity QED. It is based on the interaction of a two-mode cavity field with a three-level V-type atom. In the scheme, the atom-cavity field interaction is resonant, thus the time required to complete the quantum state transfer process is greatly shortened, which is very important in view of decoherence. Moreover, the present scheme does not require one mode of the cavities to be initially prepared in one-photon state, thus it is more experimentally feasible than the previous ones.     

A Feasible Scheme for Teleportation of Multi-atom Cat-like States in Thermal Cavities

An experimentally feasible scheme for implementing teleportation of multi-atom cat-like states in cavity QED is proposed. In the scheme the atoms interact simultaneously with a highly detuned cavity mode and are driven by a strong classical field, and the atomic state evolution is independent of cavity field state. Thus the scheme is insensitive to both the cavity decay and the thermal field, which is of importance from the experimental point of view. All the orthogonal and complete multi-atom GHZ states can be exactly distinguished only by one step, so our scheme can also be used for other purposes such as dense coding using multi-atom GHZ states as quantum channels.     

Quantum Logic Network for Cloning a State Near a Given One Based on Cavity QED

A quantum logic network is constructed to simulate a cloning machine which copies states near a given one. Meanwhile, a scheme for implementing this cloning network based on the technique of cavity quantum electrodynamics （QED） is presented. It is easy to implement this network of cloning machine in the framework of cavity QED and feasible in the experiment.     

Possible Realization of Cluster States and Quantum Information Transfer in Cavity QED via Raman Transition

We present a scheme to generate cluster states with many scheme, no transfer of quantum information between the atoms in cavity QED via Raman transition. In this atoms and cavities is required, the cavity fields are only virtually excited and thus the cavity decay is suppressed during the generation of cluster states. The atoms are always populated in the two ground states. Therefore, the scheme is insensitive to the atomic spontaneous emission and cavity decay. We also show how to transfer quantum information from one atom to another.     

基于腔QED的多用户间的多原子量子信道的建立

提出基于腔QED技术的多用户间的多原子W态和GHZ态量子信道的建立方案.在量子网络的空闲时段,各个用户和量子交换机共享EPR对.量子交换机通过原子和腔场的相互作用将两个EPR对制备成W态,再与另一个EPR对进行纠缠交换,经过直接测量后为用户建立三原子W态量子信道;同时讨论了四用户间的W态量子信道的建立方案.量子交换机对三个EPR对进行纠缠交换,将三个原子同时与腔场作用,经过直接测量后为用户建立三原子GHZ态量子信道;并将此方法推广到N个用户间的GHZ态量子信道的建立. 关键词： 腔QED 量子信道 量子交换机 纠缠交换     

Generation of a Five-Atom Cluster State in Cavity QED

We present a scheme for the generation of a five-atom cluster state in cavity QED. During the preparation no quantum information is transferred from the atoms to the cavity, and thus the scheme is insensitive to the cavity field states and cavity decay.     

Quantum state engineering by superpositions of coherent states along a straight line with a single atomic state measurement

A new scheme is proposed for preparation of a type of nonclassical state in cavity QED. In the scheme, an atom either flying through or trapped within a cavity, is controlled by the classical Stark effect; this makes it interact alternately with a (resonant) classical field and with the (dispersive) cavity field. The cavity field, which allows an arbitrary displacement operation during the process, after the detection on the atom, finally collapses to the specific superpositions of coherent states, with their weighting factors controllable. The scheme is also applied for preparation of superpositions of motional coherent states for a trapped ion. The scheme is in contrast to all the previous ones, and thus provides a new perspective for quantum state engineering.     

Schemes for preparing atomic qubit cluster states in cavity QED

Two schemes are proposed for generating atomic qubits cluster states in cavity quantum electrodynamics (QED). In the first scheme, only two-atom-cavity interactions are involved, and cluster states can be directly generated by using constructed two-qubit controlled phase gates. The second scheme needs the assistance of additional single-qubit rotations, but takes less time than the first one for two-atom operations in the cavity. In this scheme, two projective operators are constructed to prepare two-dimension or more complicated configurations of cluster states. Both schemes are insensitive to the cavity decay due to the fact that the cavity is only virtually excited during the interaction between atoms and the cavity. The idea can also be applied to the ion trap system.     

On the phase-space analysis of photon mediated quantum state transfer in nanophotonic waveguidance

A cavity quantum electrodynamics (QED) based approach for transferring quantum state between quantum nodes has been proposed, wherein a rubidium (⁸⁷Rb) atom trapped inside a two-mode optical cavity forms the quantum node and photons serve as the information carrier between two such nodes. Information is encoded into polarized photon states generated through the application of a system of lasers. The focus is made on the phase-space analysis of the approach, wherein two subspaces of the hyperfine energy levels with magnetic sub-levels of rubidium (⁸⁷Rb) atom represent the logic states ‘0’ and ‘1’. The system of lasers initiates a cavity assisted Raman process which, in turn, generates a right- or left-circularly polarized photon depending on the logic state of the transmit node. Once the photon is received (at the receive node), the logic state of the transmit node is restored into the receive node through a cavity QED process.     

Creating the multidimensional entangled coherent states of two cavity modes

We propose a scheme for creating the multidimensional entangled coherent states of two cavity modes in context of cavity quantum electrodynamics(QED). It is pointed out that under certain condition such superposition states can approximate pair coherent states and pair cat states with a high degree of accuracy.