Bidirectional Quantum Teleportation by Using Five-qubit Cluster State

We propose a scheme for bidirectional quantum teleportation by using a five-qubit cluster state. In our scheme, Alice can transmit an arbitrary two-qubit entangled state to Bob and at the same time Bob can teleport an arbitrary single-qubit state to Alice.     

Linear Optical Realization of Qubit Purification with Quantum Amplitude Damping Channel

We provide an experimental scheme which includes the realizatlon of quantum amplitude damping channel and the optimal two-qubit purification. Moreover, we discuss the purification of arbitrary input qubits and arbitrary N qubits. Our scheme only uses linear optical elements and the proposal may be useful in transmission of photons in fibres. This scheme is feasible in the laboratory with the current experimental technology.     

GENERATION OF ARBITRARY QUANTUM STATE VIA ATOMIC FEEDBACK

We present a scheme to realize the arbitrary control of the time evolution of an atom-cavity system via atomic feedback for the generation of an arbitrary quantum state. The scheme does not need to detect the atomic state, thus the uncontrollable measurement can be avoided.     

Probabilistic teleportation of an arbitrary pure state of two atoms

In the context of microwave cavity QED, this paper proposes a new scheme for teleportation of an arbitrary pure state of two atoms. The scheme is very different from the previous ones which achieve the integrated state measurement, it deals in a probabilistic but simplified way. In the scheme, no additional atoms are involved and thus only two atoms are required to be detected. The scheme can also be used for the teleportation of arbitrary pure states of many atoms or two-mode cavities.     

Asymmetric Bidirectional Controlled Teleportation by Using Six-qubit Cluster State

We propose a scheme for asymmetric bidirectional controlled teleportation by using a six-qubit cluster state as quantum channel. In our scheme, Alice can transmit an arbitrary two-qubit entangled state to Bob and at the same time Bob can teleport an arbitrary single-qubit state to Alice under the control of the supervisor Charlie.     

Multiparty-controlled teleportation of an arbitrary GHZ-class state by using a d-dimensional (N+2)-particle nonmaximally entangled state as the quantum channel

We present a scheme for multiparty-controlled teleportation of an arbitrary high-dimensional GHZ-class state with a d-dimensional (N+2)-particle GHZ state following some ideas from the teleportation (Chinese Physics B, 2007, 16: 2867). This scheme has the advantage of transmitting much fewer particles for controlled teleportation of an arbitrary multiparticle GHZ-class state. Moreover,we discuss the application of this scheme by using a nonmaximally entangled state as its quantum channel.     

Bidirectional Controlled Quantum Teleportation by Using Five-Qubit Entangled State

We propose a scheme for bidirectional controlled quantum teleportation by using a genuine five-qubit entangled state. In our scheme, Alice may transmit an arbitrary single qubit state of qubit A to Bob and at the same time, Bob may transmit an arbitrary single qubit state of qubit B to Alice via the control of the supervisor Charlie.     

Quantum teleportation of arbitrary two-qubit state via entangled cavity fields

We propose a new protocol for quantum teleportation of an arbitrary two qubit state via continuous variables entangling channel. In our scheme two pairs of entangled light fields are employed. An outstanding characteristic of this scheme is that arbitrary state of two atoms is transmitted deterministically and directly to another pair of atoms without the help of the other atoms.     

Probabilistic teleportation of an arbitrary GHZ-class state with a pure entangled two-particle quantum channel and its application in quantum state sharing

This paper presents a scheme for probabilistic teleportation of an arbitrary GHZ-class state with a pure entangled two-particle quantum channel. The sender Alice first teleports the coefficients of the unknown state to the receiver Bob, and then Bob reconstructs the state with an auxiliary particle and some unitary operations if the teleportation succeeds. This scheme has the advantage of transmitting much less particles for teleporting an arbitrary GHZ-class state than others. Moreover, it discusses the application of this scheme in quantum state sharing.     

Local unitary classification of arbitrary dimensional multipartite pure states

We propose a practical entanglement classification scheme for general multipartite pure states in arbitrary dimensions under local unitary equivalence by exploiting the high order singular value decomposition technique and local symmetries of the states. By virtue of this scheme, the method of determining the local unitary equivalence of n-qubit states proposed by Kraus is extended to the case for arbitrary dimensional multipartite states.     

Assisted Cloning and Orthogonal Complementing of an Arbitrary Unknown Two-Qubit State with χ-Type Entangled States

We propose a scheme for cloning an arbitrary unknown two-qubit state and its orthogonal complement state with the assistance from the state preparer. Our scheme includes two stages. The first stage requires a quantum teleportation process, in which an arbitrary unknown two-qubit state can be deterministically teleported from the sender to the receiver with χ-type entangled states as the quantum channel. In the second stage, with the assistance of the state preparer, either a perfect copy or an orthogonal complement state of an arbitrary unknown two-qubit state can be obtained with a certain probability.     

Multiparty Joint Remote Preparation of an Arbitrary GHZ-Class State via Positive Operator-Valued Measurement

We present a scheme for multiparty joint remote preparation of an arbitrary GHZ-class state with a pure entangled quantum channel via positive operator-valued measurement (POVM). The M senders share the information of the original GHZ-class state. All the senders perform single particle measurements according to their knowledge of the original state, the receiver can reconstruct the original state if he cooperates with the all the senders. This scheme has the advantage of transmitting less particles for remote preparation of an arbitrary GHZ-class state. Moreover, the success probability for remote preparing an arbitrary GHZ-class state is higher than others.     

Probabilistic Teleportation of an Arbitrary Three-Level Two-Particle State and Classical Communication Cost

We propose a scheme to probabilistically teleport an unknown arbitrary three-level two-particle state by using two partial entangled two-particle states of three-level as the quantum channel. The classical communication cost required in the ideal probabilistic teleportation process is also calculated. This scheme can be directly generalized to teleport an unknown and arbitrary three-level K-particle state by using K partial entangled two-particle states of three-level as the quantum channel.     

The quantum vacuum as the origin of the speed of light

We present an economical scheme of five-party quantum state sharing (FQSTS) of an arbitrary m-atom with five-atom cluster state in cavity QED. It is found that the five-partite cluster state can be used for FQSTS of an arbitrary m-atom state. The implementation of this scheme does not involve Bell-basis or GHZ-basis measurements, which makes it more convenient in a practical application than some previous schemes. The scheme is also insensitive to the cavity decay and the thermal field.     

Remote Preparation of an Arbitrary Two-atom State in the Cavity QED

A simple scheme for remote preparation of an arbitrary two-atom state in the cavity QED. An arbitrary two-atom entangled state can be prepared perfectly. Our protocol only need single qubit measurement instead of the conventional Bell-state measurement, then it is quite simple but also very robust to the cavity decay and the influence of the thermal field. The probability of the success in our scheme is 1.0.     

Bidirectional Controlled Remote State Preparation of an Arbitrary Two-Qubit State

We propose a scheme of bidirectional controlled remote state preparation of an arbitrary two-qubit state, where a nine-qubit entangled state is used as the quantum channel. In our scheme, Alice and Bob can prepare simultaneously an arbitrary two-qubit state for each other’s place with the help of the controller Charlie. The total success probability for our scheme reaches 100%. PACS numbers 03.67.Hk, 03.65.Ud, 42.50.Dv.

     

Probabilistic teleportation of arbitrary superposition of three states of an atom with a single measurement

Following a previous work [S.B. Zheng, Phys. Rev. A 69 (2004) 064302], we propose a scheme for probabilistic teleportation of arbitrary superposition of three states of an atom through only a single measurement. The scheme is also generalized for teleportation of arbitrary superposition of more states of an atom. The correlative experimental matter and decoherence are briefly discussed.     

Probabilistic Teleportation of an Arbitrary Three-Level Two-Particle State and Classical Communication Cost

We propose a scheme to probabilistically teleport an unknown arbitrary three-level two-particle state by using two partial entangled two-particle states of three-level as the quantum channel. The classical communication cost required in the ideal probabilistic teleportation process is also calculated. This scheme can be directly generalized to teleport an unknown and arbitrary three-level K-particle state by using K partial entangled two-particle states of three-level as the quantum channel.     

Generalized tripartite scheme for sharing arbitrary 2n-qudit state

Utilizing three non-maximally entangled qutrit pairs as quantum channels, we first propose a generalized tripartite scheme for sharing an arbitrary two-qutrit state with generalized Bell-state measurements. In the scheme if and only if the two recipients collaborate together, they can recover the split qutrit state with the probability determined uniquely by the smallest coefficients of the non-maximally entangled pairs. Afterwards, we further extend the scheme for sharing an arbitrary 2n-qudit state by taking 3n non-maximally entangled qudit pairs as quantum channels. Moreover, the scheme success probability relative to the inherent entanglement in quantum channels and its structure is simply discussed.     

Controlled Joint Remote State Preparation of an Arbitrary Equatorial Two-Qubit State

We propose a scheme for controlled joint remote state preparation of an arbitrary equatorial two-qubit state by using a seven-qubit entangled state as the quantum channel. In this scheme, two senders wish to help a receiver to remotely prepare an arbitrary equatorial two-qubit state, and the receiver can obtain the original quantum state with 100% success probability by performing the appropriate unitary operations.