报告题目：Joint remote state preparation of mixed state
报 告 人：章志华 副教授（江苏大学）
报告摘要：Joint remote state preparation (JRSP for short) has gained lots of attention since its first appearance. But almost all the proposals focused on JRSP of pure states. In this paper, we present a scheme of JRSP for mixed state via the three-qubit GHZ state. The scheme is deterministic for real coefficient mixed state and probabilistic for complex coefficient mixed state. A thorough model of our scheme is introduced in the language of density operators for real coefficient mixed state. The corresponding quantum circuits are given for deterministic JRSP schemes. Meanwhile, we investigate the efficiency of deterministic JRSP when some qubits in the protocol are subjected to noise environment. Four types of usual encountered noise in quantum communication are considered, i.e., the bit-flip, phase-flip (phase-damping), depolarizing and amplitude-damping noise. We find that in the bit-flip, phase-flip and amplitude-damping noise channel, the fidelity is affected by both variables of Bloch vector of target mixed state and noise parameter of channel. Specifically, in depolarizing noise, the fidelity is one regardless of the Bloch vector and noise rate. Especially, for some pure states, the fidelity in our scheme is higher compared with other results.