Classical communication and entanglement cost in preparing a class of multi-qubit states
Abstract
Description
Recently, several similar protocols[J. Opt. B 4 (2002) 380; Phys. Lett. A 316 (2003) 159; Phys. Lett. A 355 (2006) 285; Phys. Lett. A 336 (2005) 317] for remotely preparing a class of multi-qubit states (i.e, $α|0 ... 0>+β|1... 1>$) are proposed, respectively. In this paper, by applying the controlled-not (CNOT) gate, a new simple protocol is proposed for remotely preparing such class of states. Compared to the previous protocols, both classical communication cost and required quantum entanglement in our protocol are remarkably reduced. Moreover, the difficulty of identifying some quantum states in our protocol is also degraded. Hence our protocol is more economical and feasible.