Teleportation of a Kind of Three-Mode Entangled States of Continuous Variables

A quantum teleportation scheme to teleport a kind of tripartite entangled states of continuous variables by using a quantum channel composed of three bipartite entangled states is proposed. The joint Bell measurement is feasible because the bipartite entangled states are complete and the squeezed state has a natural representation in the entangled state basis. The calculation is greatly simplified by using the Schmidt decomposition of the entangled states.     

Teleportation of tripartite entangled coherent states

This paper proposes a feasible scheme for the quantum teleportation of tripartite entangled coherent states by using linear optical devices such as beam splitters, phase shifters and photo detectors. The scheme is based on the bipartite maximally entangled coherent state and the tripartite entangled coherent state with bipartite maximal entanglement as quantum channels. It shows that when the mean number of photons is equal to 2, the total minimum of the average fidelity for an arbitrary tripartite entangled state is 1-0.67×10 ^-3.     

Teleportations of Mixed States and Multipartite Quantum States

In this paper, we propose a protocol to deterministically teleport an unknown mixed state of qubit by utilizing a maximally bipartite entangled state of qubits as quantum channel. Ira non-maximally entangled bipartite pure state is employed as quantum channel, the unknown mixed quantum state of qubit can be teleported with 1 -√ 1- C^2 probability, where C is the concurrence of the quantum channel. The protocol can also be generalized to teleport a mixed state of qudit or a multipartite mixed state. More important purpose is that, on the basis of the protocol, the teleportation of an arbitrary multipartite （pure or mixed） quantum state can be decomposed into the teleportation of each subsystem by employing separate entangled states as quantum channels. In the case of deterministic teleportation, Bob only needs to perform unitary transformations on his single particles in order to recover the initial teleported multipartite quantum state.     

三粒子纠缠相干态的隐形传态

提出了一个利用一个两粒子最大纠缠相干态和一个三粒子纠缠相干态作为量子信道进行三粒子纠缠相干态隐形传态的方案.该方案只需线性光学操作和双模光子数测量.计算结果表明,应用本方案的设置,隐形传态成功的概率与所用的相干态的平均光子数有关,反映了纠缠相干态的非正交特性.     

Quantum teleportation of entangled squeezed vacuum states

An optical scheme for probabilistic teleporting entangled squeezed vacuum states (SVS) is proposed. In this scheme, the teieported state is a bipartite entangled SVS, and the quantum channel is a tripartite entangled SVS. The process of the teleportation is achieved by using a 50/50 symmetric beamsplitter and photon detectors with the help of classical information.     

Generation of a new bipartite coherent-entangled state and its applications

A new bipartite coherent-entangled state is introduced in the two-mode Fock space,which exhibits the properties of both a coherent state and an entangled state.The set of coherent-entangled states makes up a complete and partly nonorthogonal representation.A simple experimental scheme to produce the coherent-entangled state using an asymmetric beamsplitter is proposed.Some applications of the coherent-entangled state in quantum optics are also presented.     

Generation of a new bipartite coherent-entangled state and its applications

A new bipartite coherent-entangled state is introduced in the two-mode Fock space, which exhibits the properties of both a coherent state and an entangled state. The set of coherent-entangled states makes up a complete and partly nonorthogonal representation. A simple experimental scheme to produce the coherent-entangled state using an asymmetric beamsplitter is proposed. Some applications of the coherent-entangled state in quantum optics are also presented.     

Multiparticle Generalization of Remote State Preparation

We present a scheme for preparing remotely a three-particle pure entangled state via entanglement swapping,and then we directly generalize it to the multiparticle case. It is shown that by using N pairs of bipartite EPR states as the quantum channel, remote preparation of some specially chosen N-particle pure entangled states can be achieved faithfully with an N-particle orthonormal basis measurement and only N bits of classical information.     

Multiparticle Generalization of Remote State Preparation

We present a scheme for preparing remotely a three-particle pure entangled state via entanglement swapping,and then we directly generalize it to the multiparticle case. It is shown that by using N pairs of bipartite EPR states as the quantum channel, remote preparation of some specially chosen N-particle pure entangled states can be achieved faithfully with an N-particle orthonormal basis measurement and only N bits of classical information.     

Teleportation of Three-Level Multi-partite Entangled State by a Partial Three-Level Bipartite Entangled State

We present a scheme for probabilistically teleporting an unknown three-level bipartite entangled state by using a partial entangled three-level bipartite state as quantum channel This scheme can be directly generalized to probabilistically teleport an unknown three-level k-particle entangled state by a partial three-level bipartite entangled state. A11 kinds of unitary transformations are given in detail We calculate the successful total probability and the total classical communication cost required for this scheme.     

纠缠相干态的量子隐形传态

提出利用双模纠缠相干态作为量子信道，实现纠缠相干态量子隐形传态的方案. 分别在非正交的相干态表象和另一个由相干态构成的正交态表象对双模纠缠相干态的隐形传态进行具体分析. 发现在相干态表象，虽然只要线性光学元件就可以完成隐形传态，但成功的概率小于1/2，而在正交态表象，只要能分辨4个由相干态构成的Bell态，成功的概率就是1. 关键词： 隐形传态 纠缠相干态 纠缠相干态量子信道     

Scheme for Realizing Probabilistic Teleportation of Bipartite Photonic States via Linear Optical Elements

We propose a probabilistic scheme for realizing teleportation of bipartite photonic states using linear optical elements where only requires a two-photon Bell state used as quantum channel. It reduces the requirement of the entanglement of quantum channel, but requires an additional photon and an auxiliary maximally entangled photon pair locally.     

Scheme for Realizing Probabilistic Teleportation of Bipartite Photonic States via Linear Optical Elements

We propose a probabilistic scheme for realizing teleportation of bipartite photonic states using linear optical elements where only requires a two-photon Bell state used as quantum channel. It reduces the requirement of the entanglement of quantum channel, but requires an additional photon and an auxiliary maximally entangled photon pair locally.     

An Efficient and Economic Scheme for Remotely Preparing a Multi-Qudit State via a Single Entangled Qudit Pair

We propose some schemes for remote preparation of arbitraryhigh-dimensional equatorial entangled state via a single bipartitehigh-dimensional entangled state as quantum channel. We firstlypresent the remote preparation of bipartite three- and d-dimensionalequatorial entangled state by using a single entangled qutrit andqudit pair, respectively, and then directly generalize the schemesto multipartite case. The cases of the quantum channel beingnon-maximally two-qutrit and two-qudit entangled state are alsoconsidered, respectively. In these schemes the required resourcesare single-particle projective measurement, appropriate localunitary operation, auxiliary particle, and high-dimensional C-NOToperation. It is shown that the entanglement resource and classicalcommunication cost are both greatly reduced in our schemes.     

Entanglement witnesses of four-qubit tripartite separable quantum states

A quantum entangled state is easily disturbed by noise and degenerates into a separable state. Compared to the entanglement with bipartite quantum systems, less progress has been made for the entanglement with multipartite quantum systems. For tripartite separability of a four-qubit system, we propose two entanglement witnesses, each of which corresponds to a necessary condition of tripartite separability. For the four-qubit GHZ state mixed with a W state and white noise, we prove that the necessary conditions of tripartite separability are also sufficient at W states side.     

Scheme for probabilistic remotely preparing a multi-particle entangled GHZ state

This paper presents a scheme for probabilistic remote preparation of a three-particle entangled Greenberger-Horne-Zeilinger （GHZ） state via three-particle orthonormal basis projective measurement, and then directly generalize the scheme to multi-particle case. It is shown that by using N pairs of bipartite non-maximally entangled states as the quantum channel and N-particle orthonormal basis projective measurement, the multi-particle remote preparation can be successfully realized with a certain probability.     

Application of Bipartite and Tripartite Entangled State Representations in Quantum Teleportation of Continuous Variables

We mostly investigate two schemes. One is to teleport a multi-mode W-type entangled coherent state using a peculiar bipartite entangled state as the quantum channel different from other proposals. Based on our formalism,teleporting multi-mode coherent state or squeezed state is also possible. Another is that the tripartite entangled state is used as the quantum channel of controlled teleportation of an arbitrary and unknown continuous variable in the case of three participators.     

Remote Preparation of Multipartite Equatorial Entangled States in High Dimensions with Three Parties

A scheme for probabilistic remotely preparing N-particle d-dimensional equatorial entangled states via entangled swapping with three parties is presented. The quantum channel is composed of N - 1 pairs of bipartite d-dimensional non-maximally entangled states and a tripartite d-dimension non-maximally entangled state. It is shown that the sender can help either of the two receivers to remotely prepare the original state, and the N-particle projective measurement and the generalized Hadamard transformation are needed in this scheme. The total success probability and classical communication cost are calculated.     

Application of Bipartite and Tripartite Entangled State Representations in Quantum Teleportation of Continuous Variables

We mostly investigate two schemes. One is to teleport a multi-mode W-type entangled coherent state using a peculiar bipartite entangled state as the quantum channel different from other proposals. Based on our formalism,teleporting multi-mode coherent state or squeezed state is also possible. Another is that the tripartite entangled state is used as the quantum channel of controlled teleportation of an arbitrary and unknown continuous variable in the case of three participators.     

Majorization criterion for distillability of a bipartite quantum state

Bipartite quantum states are classified into three categories: separable states, bound entangled states, and free entangled states. It is of great importance to characterize these families of states for the development of quantum information science. In this Letter, I show that the separable states and the bound entangled states have a common spectral property. More precisely, I prove that for undis-tillable-separable and bound entangled-states, the eigenvalue vector of the global system is majorized by that of the local system. This result constitutes a new sufficient condition for distillability of bipartite quantum states. This is achieved by proving that if a bipartite quantum state satisfies the reduction criterion for distillability, then it satisfies the majorization criterion for separability.