噪声道下量子逻辑门的非局域实现

逻辑门是量子信息的基本操作单元，是实现量子计算机和构建量子网络的基础。因而在量子信息处理中起了至关重要的作用。由于微观子系统间的交叉相互作用和量子退相干的影响，大规模的量子计算很难实现。为此，人们提出了分布式量子计算的概念。而实现远程量子逻辑门是构建分布式量子计算的基本任务。本研究将围绕实现一些常用的逻辑门操作（如可控－非门、相位门、交换、Toffoli、Fredkin等门操作）展开探索，研究这些常见的二比特、三比特以及多比特门操作在噪声环境下的非局域实现理论方案，和在具体物理系统的实现问题。我们将重点运用量子光学的全量子理论、量子测量引起的波包坍缩和经典通讯等研究方法，具体研究的是基于一些具体的量子系统，利用纠缠交换和量子中继器技术，进行常用逻辑门远程实现的研究。我们的研究结果，将为揭示量子的非局域性特性，实现量子计算机和构建量子网络奠定基础，为量子计算基础研究与技术的发展提供理论支持。

Quantum logic gate (QLG) is a fundamental operation unit, and the basis of the implementation of quantum computers and the construction of quantum nets. Since it plays an important role in quantum information processing. Due to the crossing interaction among the microscopic subsystems and the effect of quantum decoherence, it is difficult to perform large-scale quantum computation. After that, the concept, distribution quantum computation (CQC), is presented. A basic task on setting up CQC readily is the remote implementation of QLG. Our study concerns on the the nonlocal implementation of some conventional gates (such as Controlled-not, phase gate, swapping, Toffoli, Fredkin, and so on) under noisy environment, and the counterpart schemes based on concrete quantum systems. We will mainly make use of some useful methods as all-quantum theory, wave-packet collapse arising from quantum measurements and classical communication, investigate some conventional logic gates based on entanglement swap and quantum repeaters. Our results lay the foundation for quantum non-locality and the implementation of quantum computers and nets, and also provide the important theoretical support for the basic quantum computation study and the development of the technologies.