Asymmetric bidirectional quantum teleportation via six-qubit partially entangled state

In this paper, an asymmetric bidirectional controlled quantum teleportation via a six-qubit partially entangled state is given, in which Alice wants to transmit a two-qubit entangled state to Bob and Bob wants to transmit a single-qubit state to Alice on the same time. Although the six-qubit state as quantum channel is partially entangled, the teleportation is implemented deterministically. Furthermore, only Bell-state measurements, single-qubit measurements and some unitary operations are needed in the scheme.

Deterministic joint remote state preparation via partially entangled quantum channel

In this paper, we propose a scheme for deterministic joint remote state preparation (JRSP). Two spatially separated senders intend to help a receiver remotely prepare an arbitrary single-qubit state. Four-particle partially entangled state is constructed to serve as the quantum channel. By determining right unitary operations for the senders and appropriate recovery operations for the receiver, the target state can be reestablished with unit success probability, irrespective of the channel parameter.

REMOTE PREPARATION OF A TWO-PARTICLE ENTANGLED STATE

In this paper, we propose a scheme for probabilistic remote preparation of a two-particle nonmaximally entangled state. In this scheme, two pairs of the two-particle partially entangled state are used as quantum channel. Alice performs the single-particle measurement three times and sends the information to the receiver. In accordance with the information, the receiver can construct the original state. By this method, the total probability of successful preparation is enhanced.

PROBABILISTIC TELEPORTATION OF A TWO-ATOM ENTANGLED STATE IN CAVITY QED

We present two schemes for probabilistically teleporting a two-atom entangled state using a three-atom partially entangled state as the quantum channel in cavity QED with the help of separate atomic measurements. The first scheme is only based on the interaction between two driven atoms and a quantized cavity mode in the large detuning limit, so the effects of both cavity decay and the thermal field are eliminated. In the second scheme, it is necessary to introduce an additional resonant cavity besides the thermal cavity to realize the teleportation, and the corresponding success probability is improved.

QUANTUM CIRCUITS FOR PROBABILISTIC ENTANGLEMENT TELEPORTATION VIA A PARTIALLY ENTANGLED PAIR

It deserves mentioning that the quantum circuit, i.e. quantum logic network, is essential to the practical realization of teleportation in experiment. Using only one partially entangled pair, we first propose two novel strategies for probabilistically teleporting any partially entangled state of a bipartite system. The feature of the present protocol is to weaken the requirement for the quantum channel, and also to cut down the number of entangled particles initially shared by the sender and receiver. On the other hand, we explicitly construct the generalized measurement described by the positive operator-valued measure (POVM). Two kinds of efficient quantum circuits for implementing the teleportation are offered. In addition, we generalize the two-particle probabilistic teleportation to the system of many particles.