Quantum entanglement and teleportation

Zhan-Yun Wang, Yitao Gou, Jin-Xing Hou +2 more

We explicitly present a generalized quantum teleportation of a two-qubit entangled state protocol, which uses two pairs of partially entangled particles as quantum channel. We verify that the optimal probability of successful teleportation is determined by the smallest superposition coefficient of these partially entangled particles. However, the two-qubit entangled state to be teleported will be destroyed if teleportation fails. To solve this problem, we show a more sophisticated probabilistic resumable quantum teleportation scheme of a two-qubit entangled state, where the state to be teleported can be recovered by the sender when teleportation fails. Thus the information of the unknown state is retained during the process. Accordingly, we can repeat the teleportion process as many times as one has available quantum channels. Therefore, the quantum channels with weak entanglement can also be used to teleport unknown two-qubit entangled states successfully with a high number of repetitions, and for channels with strong entanglement only a small number of repetitions are required to guarantee successful teleportation.

F.J. Duarte

Akira Furusawa, Peter van Loock

Feng Xun-Li, Gong Shang-Qing, Zhongyang Wang +1 more

The teleportation of an unknown quantum state from one observer to another is of great importance in quantum information. In the standard teleportation scheme, a maximally entangled state is demanded. However, it is difficult to prepare such states in practice, and real entangled states are always partly entangled. We present a scheme to teleport an unknown quantum state using two partly entangled states. We show that the teleportation can be realized with a certain probability.

Yanhua H. Shih

Vikram Verma

Abstract In this paper, we propose a new scheme for faithful bidirectional quantum teleportation (BQT) of special type of two-qubit entangled states by using single G state as a quantum channel. In 2016, by using five-qubit and six-qubit entangled states as the quantum channels, two different BQT schemes were proposed by Sang ((2016) Int. J. Theor. Phys . 55 , 1333) and Hassanpour et al ((2016) Quantum Inf. Process. 15 , 905) respectively. In first scheme, Alice teleports a special type of two-qubit entangled state to Bob and at the same time Bob teleports a single qubit state to Alice. In later scheme, Alice and Bob teleport special type of two-qubit entangled state to each other simultaneously. In contrast to these schemes, in our proposed scheme Alice and Bob can teleport special type of two-qubit entangled states to each other simultaneously while the quantum channel is a four-qubit entangled state. Our proposed BQT scheme requires minimum consumption of quantum and classical resources and it has maximum intrinsic efficiency as compared with previous BQT schemes. We also generalize our scheme for bidirectional quantum teleportation of N-qubit entangled states.