Joint remote preparation of a general two-qubit state

Abstract

We propose a set of novel protocols to remotely prepare a general two-qubit state by joint actions of two separate people who independently share the classical knowledge of the state, without and with quantum control of a supervisor. Various quantum resources are used as the quantum channel. Although the execution complexity differs for different protocols, the total success probability is protocol independent.

Nonmaximal Entanglement Can Make Joint Remote State Preparation Absolutely Secure

“…Possible quantum channels may be served by four entangled pairs [17], two entangled trios [18] or one six-qubit cluster state [19]. Here we are concerned with the most economical quantum resource that consists only of three nonmaximally entangled pairs [20] …”

“…JRSP is an interesting multiparty quantum task that has recently attracted attention in the quantum information community from both theoretical [12][13][14][15][16][17][18][19][20][21] and experimental architecture [22] points of view. In contrast to the well-known remote state preparation (RSP) [23] in which one party has complete classical knowledge of a quantum state |Ψ to be faithfully prepared at a remote party's location, in JRSP there are several inferiors who are assigned by a superior to jointly prepare the state |Ψ for a remote receiver.…”

“…So the superior can secretly split the information of the state |Ψ into pieces each of which is given to an inferior to exclude leakage of full information about |Ψ to any of the inferiors. Both maximally and nonmaximally entangled states have been used as the quantum channel for JRSP and the security level of all the existing protocols [12][13][14][15][16][17][18][19][20][21][22] is that any subgroup of the inferiors cannot exactly identify the state |Ψ but all the inferiors together can. Like in blind quantum computation [24], it is highly desirable also for JRSP to have absolute security in the sense that neither an individual nor the entire group of the participants (i.e., all the inferiors plus the receiver) can precisely infer the sate |Ψ .…”

Symmetric Remote Two-Qubit Preparation via Positive Operator-Valued Measure

“…Also some RSP schemes are investigated by using different entangled states as quantum channel [34][35][36][37][38][39][40][41][42]. In terms of entanglements in quantum channel, these RSP schemes can be classified into two types.…”

“…In terms of entanglements in quantum channel, these RSP schemes can be classified into two types. One takes pure entangled states as the quantum channel [34][35][36][37][38] while the other utilizes partly pure entangled states [39][40][41][42]. In the latter case, usually people need to introduce one or more auxiliary qubits and then entangle them with his/her original qubits.…”