利用两能级原子与相干态腔场相互作用实现纠缠浓缩

根据大失谐条件下原子–腔场相互作用的特点,讨论了一个制备纠缠相干态的方法,提出了一个利用两能级原子与腔场相干态相互作用实现纠缠浓缩的方案。在这个方案中,2个具有相同振幅但有着π相位差的相干光|α〉和|-α〉构成的纠缠态光场被用来作为量子信道,通过利用两能级原子与腔场的相互作用以及两模正交态测量实现了这个纠缠浓缩的过程。结果表明:对于纠缠相干态,无论其初始的纠缠是多么微弱,利用这种方法总有一定的几率可以从部分纠缠态中提取出最大纠缠态。

利用腔的输入输出过程实现两比特的Deutsch-Jozsa算法（英文）

文章提出依靠辅助腔和单光子脉冲相互作用来实现两比特Deutsch-Jozsa算法的方案.该方案简单实用,随着腔QED技术的发展,它易被操控.该方案可以推广到多比特Deutsch-Jozsa算法的情况.

Remote Three-Party Quantum State Sharing Based on Three-Atom Entangled States Assisted by Cavity QED and Flying Qubits

We present a remote three-party quantum state sharing （QSTS） scheme with three-atom Greenberger- Horne-Zeilinger （GHZ） states assisted by cavity QED and flying qubits. It exploits some photons to act as the flying qubits for setting up the quantum channel securely with three-atom systems in a GHZ state, which maybe make this remote QSTS scheme more practical than some other schemes based on atom systems only or ion-trap systems as photons interact with their environments weakly. The coherence of the stationary atom qubits in cavities provides the convenience for the parties in QSTS to check eavesdropping, different from entangled photon systems. Moreover, the present scheme works in a collective-noise condition and it may be more practical than others in applications in future.

Preparation of a New Type of Multiqubit Entangled States in Cavity QED

Recently Yang,Chu,and Han [Phys.Rev.A 70 (2004) 022329] presented a new type of multipartiteentangled states for implementing efficient many-party controlled teleportation of multiqubit quantum information.Herewe propose a simple scheme for preparing such a type of multi-atom entangled states in cavity quantum electrodynamics(QED).The scheme involves atom-cavity interaction with large detuning,and is immune to the cavity decay and thethermal field states.Some practical analyses show its availability with the present technology.

Teleportation of N-qubit W State without Bell-State Measurement via Selective Resonant Interaction in Cavity QED

We present a scheme in which the N-atom W state is teleported by employing the selective interactionof a cavity field with a driven three-level atom in the A configuration and detecting a single atom in one of the groundstates.The long-lived W state is teleported from atom A to atom B when the atoms B and A are sent through acavity successively and atom A is then detected.The advantage is that the present one does not involve the Bell-statemeasurement and is robust against the atomic spontaneous emission.

Probabilistic Teleportation of an Arbitrary Two-Atom State in Cavity QED

We propose a scheme for the teleportation of an arbitrary two-atom state by using two pairs of two-atom nonmaximally entangled states as the quantum channel in cavity QED. It is Shown that no matter whether the arbitrary two-atom pure state to be teleported is entangled or not, our teleportation scheme can always be probabilistically realized. The success prohability of teleportation is determined by the smaller coemcients of the two initially entangled atom pairs.

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.

Scheme for Realizing Probabilistic Teleportation of Bipartite Atomic State via Cavity QED

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.

Implementing Deutsch-Jozsa Algorithm in Cavity QED

We propose a simple scheme for implementing Deutsch-Jozsa algorithm in cavity QED. Our scheme is insensitive to both the cavity decay and thermal field because we use the large-detuned interaction. The scheme would be important to constructing practical computer in cavity QED system.

Efficient Atomic One-Qubit Phase Gate Realized by a Cavity QED and Identical Atoms System

We present a scheme to implement a one-qubit phase gate with a two-level atom crossing an optical cavity in which some identical atoms are trapped. One can conveniently acquire an arbitrary phase shift of the gate by properly choosing the number of atoms trapped in the cavity and the velocity of the atom crossing the cavity. The present scheme provides a very simple and efficient way for implementing one-qubit phase gate.

Scheme for Implementing Quantum Cloning Restoring Machine in Cavity QED

We propose an experimentally feasible scheme for implementing quantum restoring machine of the optimal universal 1→ 2 quantum cloning machine in the context of cavity QED. In our scheme, two atoms （the clones） simultaneously interact with a cavity field, and meanwhile they are driven by a classical field. Then an arbitrary unknown input state can be restored in the ancilla by applying appropriate unitary local operation.

Bunching and Antibunching in Cavity QED

We study the statistics of the emitted filed from Rydberg atom confined inside a microcavity and interacting with a pump laser in the strong coupling regime. We explore the manifestation of the antibunching in connection with the internal system parameters.

Generation of W States with Many Superconducting-Quantum-Interference-Devices in Cavity QED

We propose a scheme to generate the W states with many SQUIDs (superconducting-quantum-interferencedevices)in cavity QED via Raman transition.In this scheme,the transfer of quantum information between the SQUIDsand cavity is not required.And the cavity field is only virtually excited,thus the cavity decay is suppressed during theW states generation.The SQUIDs are always populated in the two ground states.Therefore,the scheme is insensitiveto the spontaneous emission of the excited level of the SQUID and cavity decay.

A Singlet State Generated with SQUIDs in Cavity QED

We propose a scheme to generate a three-qubit three-IeveI singlet state in cavity QED, by placing three A-type SQUIDs in a single mode cavity. In this scheme, we make use of the interaction between the SQUIDs and cavity filed, and the classical pulses. The cavity fields are in vacuum state during the whole operation processes of creating the entanglement, and there is no quantum information transformation between the SQUIDs and cavity fields. Because of the advantage of the SQUID-cavity system, the quality factor of the cavity is greatly relaxed.

Speed Geometric Quantum Logical Gate Based on Double-Hamiltonian Evolution under Large-Detuning Cavity QED Model

We introduce the double-Hamiltonian evolution technique approach to investigate the unconventional geometric quantum logical gate with dissipation under the model of many identical three-level atoms in a cavity~ driven by a classical fieM. Our concrete calculation is made for the case of two atoms for the large-detuning interaction of the atoms with the cavity mode. The main advantage of our scheme is of eliminating the photon flutuation in the cavity mode during the gating. The corresponding analytical results will be helpful for experimental realization of speed geometric quantum logical gate in real cavities.

Transferring Multi-Dimensional Quantum States and Preparing Quantum Networks in Cavity QED

In this paper we propose a scheme for transferring quantum states and preparing quantum networks. Compared with the previous schemes, this scheme is more efficient, since three or four-dimensional quantum states can be transferred with a single step and information interchange of three-dimensional quantum states can be realized, which is a significant improvement. It is based on the resonant interaction of a three-mode cavity field with an atom. As a consequence, the interaction time is shortened greatly. Furthermore, we give some discussions about the feasibility of the scheme.

Transferring of a Two-Mode Entangled State Between Two Cavities via Cavity QED

We propose a scheme for transferring of a two-mode entanglement of zero- or one-photon entangled states between two cavities via atom-cavity field resonant interaction. In our proposal, in order to transfer the entangled state, we only need two identical two-level atoms and a two-mode cavity for receiving the teleported state. This scheme does not require Bell-state measurement and performing any transformations to reconstruct the initial state. And the transfer can occur with 100% success probability in a simple manner. And a network for transferring of a two-mode entangled state between cavities is suggested. This scheme can also be extended to transfer N-mode entangled state of cavity.

Scheme for Remote Implementation of Partially Unknown Quantum Operation of Two Qubits in Cavity QED

By constructing the recovery operations of the protocol of remote implementation of partially unknownquantum operation of two qubits[An-Min Wang:Phys.Rev.A 74(2006)032317]with two-qubit Cnot gate and singlequbit logic gates,we present a scheme to implement it in cavity QED.Long-lived Rydberg atoms are used as qubits,and the interaction between the atoms and the field of cavity is a nonresonant one.Finally,we analyze the experimentalfeasibility of this scheme.

Revisiting Probabilistic Teleportation Scheme for Atomic State via Cavity QED

A probabilistic teleportation scheme for atomic stats via cavity QED [Phys. Rev. A 70 （2004） 054303] is revisited and accordingly some improvements are made.

Scheme for Deterministic Quantum Teleportation of an Arbitrary Two-Particle State via Two EPR Pairs in Cavity QED

A deterministic teleportation scheme for an arbitrary two-particle state is proposed in cavity QED. The success probability can reach 1.0. In addition, the scheme is insensitive to both the cavity decay and the thermal field.