量子纠缠控制及消相干的研究

Study on the Control of Quantum Entanglement and Decoherence

对量子纠缠的控制进行了阐述。当把外加控制也考虑到量子纠缠系统中去,它和被操作的系统发生纠缠,就可以实现量子操作。而对于量子位和环境组成的复合系统经过一个么正演化,最初处于纯态的子系统,由于子系统相互作用,将引起量子位的消相干,使量子位从一个纯态演化成为混合态,为人们研究量子计算机和环境的相互作用而产生消相干过程提供一个物理模型。

In this paper a control process of Quantum Entanglement （QE） is presented. The process reveals that when an extra control is added to a QE system, it gets entangled with the present system and then the quantum operation can be achieved. If a compound system of environment and quantum bit undergoes a unitary transformation, at-first-pure-state subsystems will cause quantum bit decoherence because of their interaction, enabling quantum bit to develop into a mixed-state one. The process provides a physical model about the decoherence formed by the interaction between quantum computers and environment.