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 Multi-Dimensional Quantum States and Preparing QuantumNetworks in Cavity QED

In this paper we propose a scheme for transferring quantum states andpreparing 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 cavityfield with an atom. As a consequence, the interaction time is shortenedgreatly. Furthermore, we give some discussions about the feasibility of the scheme.     

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.     

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 quanturn 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.     

Scheme for Quantum Dense Coding with Secret Sharing in Cavity QED

Quantum dense coding （QDC） is a process originally proposed to send two classical bits information from a sender to a receiver by sending only one qubit. Our scheme of QDC is proposed following some ideas on secret sharing with entanglement in cavity QED. Based on the theory of secret sharing the QDC process can be more secure.     

基于腔QED的一种非均匀量子行走

基于已有的文献,提出一种非均匀的量子行走,这种行走的特点是:针对不同的位置,手征态的变换具有不同的形式.在对该行走作一定的说明之后,我们进一步提出在腔QED体系中,实现该种行走的一种可能方案.     

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 unknown quantum operation of two qubits [An-Min Wang： Phys. Rev. A 74 （2006） 032317] with two-qubit Cnot gate and single qubit 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 experimental feasibility of this scheme.     

基于腔QED的隐形传送四比特团簇类态方案

本文提出了一个基于腔QED的隐形传送四比特团簇类态方案,在该方案中选用两个GHZ纠缠对作为量子通道,通过对原子和腔场的大失谐作用以及外加强经典场的辅助,可以制备纠缠的量子通道,完成联合的三粒子测量,成功地实现隐形传送四比特团簇类态。结果还表明,此方案不受腔场退相干和热场的影响.     

Alternative Scheme for Teleportation of Two-Atom Entangled State in Cavity QED

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 ∧-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.     

Alternative Scheme for Teleportation of Two-Atom Entangled State in Cavity QED

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.     

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 unknown quantum operation of two qubits [An-Min Wang: Phys. Rev. A 74 (2006) 032317] with two-qubit Cnot gate and single qubit 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 experimental feasibility of this scheme.     

Scheme for Quantum Entanglement Swapping on Cavity QED System

We propose a scheme for realizing quantum entanglement swapping between the atoms in cavity QED. With only virtual excitation of the cavity during the interaction between the atoms and cavity, the scheme is insensitive to the cavity mode states and the cavity decay. The ideas can also be utilized for realizing entanglement swapping between the atomic levels in a single atom and the atomic levels in the Bell states and between the atomic levels in the Bell states and the atomic levels in the W states.     

Scheme for splitting quantum information via W states in cavity QED systems

Assisted by multipartite entanglement, Quantum information may be split so that the original qubit can be reconstructed if and only if the recipients cooperate. This paper proposes an experimentally feasible scheme for splitting quantum information via W-type entangled states in cavity QED systems, where three-level Rydberg atoms interact with nonresonant cavities. Since W-type states are used as the quantum channel and the cavities are only virtually excited, the scheme is easy to implement and robust against decoherence, and the dependence on the quality factor of the cavities is greatly reduced.     

基于腔QED技术的量子信息的多方秘密共享

提出了一个基于腔QED技术的量子信息的多方秘密共享方案.该方案不受腔的衰减和热场的影响,并考虑了几种可能偷听下的安全性.     

一个传送原子纠缠态的新方案

本文提出一个通过原子和腔场相互作用传送未知原子纠缠态的新方案,并且成功概率为100%.在这个方案里,我们主要利用两个原子用来接受被传送的原子纠缠态以及一个双模腔作为量子通道.由于腔场的两个模具有不同的频率和正交极化,因此这两个模能够被区分,并且处于腔场的不同区域.原子和腔场通过J-C哈密顿量发生共振相互作用,当原子和其中一个模相互作用时,另外一个模不受影响.该方案既不需要贝尔态测量,也不需要任何操作重构纠缠初态.这个方案也可以推广到传送N个原子的纠缠态.     

Scheme for Implementing Perfect Quantum Teleportation with Non-maximally Entangled W-Class State in Cavity QED

We propose an experimentally feasible teleportation scheme with three-atom W-class state, which was first proposed by Agrawal and Pati [P. Agrawal and A. Pati, Phys. Rev. A 74 （2006） 062320 ], in cavity QED. In this scheme atoms interact simultaneously with a nonresonant cavity and there is no energy exchange between the atoms and the cavity. Thus it is insensitive to the cavity decay, which is of importance in view of experiment.     

Generation of Entangled Multi-atom Dicke States in Cavity Quantum Electrodynamics

We propose a scheme to generate two-atom maximally entangled state in cavity quantum electrodynamies （QED）. The scheme can 5e extended to generation of entangled multi-atom Dicke states if we control the interaction time of atoms with cavity modes. We use adiabatically state evolution under large atom-cavity detuning, so the scheme is insensitive to atomic spontaneous decay. The influence of cavity decay on fidelity and success probability is discussed.     

Quantum Logic Gates and Cluster States with Four-level Atoms in Cavity QED

We propose a model to implement the two-qubit quantum logic gates, i.e., the quantum phase gate and the Controlled-NOT gate, and generate the atomic qubits cluster states with a large detuned interaction between four-level atoms and a single-mode cavity field. In the presented protocol, the quantum information is encoded on the stable ground states of the atoms, and the effect of decoherence from atomic spontaneous emission is negligible. In addition, the interaction between atoms and the cavity is large detuned, and the cavity is only virtually excited. Therefore, the scheme is insensitive to the cavity decay. The experimental feasibility of our proposal is also discussed.     

Scheme for Implementing Quantum Dense Coding and Teleportation with Tripartite Entangled State in Cavity QED

In this paper, we present a peculiar tripartite entangled state that is inequivalent to both the GHZ state and the W state, and then propose to implement efficient quantum information processing such as quantum dense coding and teleportation with this entangled state in cavity QED. In this scheme the atoms interact with a highly detuned cavity field with the assistance of a strong classical driven field. It does not require the transfer of quantum information between the atomic system and the cavity, and then our scheme is insensitive to both the cavity decay and the thermal field.