Teleportation and computation

Warit Asavanant, Akira Furusawa

Quantum teleportation is the most basic quantum protocol that transfers quantum states between two parties via sharing of quantum entanglement, measurements, and feedforward operations. At first glance, quantum teleportation is simply an identity operation that does not change the quantum states. Quantum teleportation, however, forms the basis for a paradigm of quantum computation called measurement-based quantum computation (MBQC). In the first half of this chapter, we describe continuous-variable (CV) quantum teleportation. In the second half, we explain how to use quantum teleportation in MBQC. There are two important concepts regarding MBQC: cluster state and gate teleportation. Cluster state is a multipartite entangled state that can be used for CV quantum computation, given that we can implement appropriate measurements and feedforward operations on it. Gate teleportation, on the other hand, is a concept that we can “teleport” non-Gaussian operations on the resource state to the input state.

Xihan Li, Fu‐Guo Deng

H. Lu

A scheme for teleporting an unknown quantum state via a partially entangled particle pair is proposed. We show that teleportation can be successful realized with unit fidelity but less than unit probability if the sender performs a rotational operation on the teleported qubit and then performs computation basis measurements on the teleported particle and the half of the entangled particle pair respectively. The probability of successful teleportation is determined by both Schmidt coefficients of the entangled pair. This method can be generalized to the teleportation of an arbitrary and unknown multi-qubit state.

Mang Feng, Xiwen Zhu, Xi-Ming Fang +2 more

A scheme of teleportation of two unknown quantum states via quantum computation is proposed. The comparison with the former proposals shows that our scheme is more in tune with the original teleportation proposal and the efficiency is higher. The teleportation of an unknown entangled state is also discussed.