期刊论文

中文

量子电子学报

1007-5461

2008

25

4

423-429

10.3969/j.issn.1007-5461.2008.04.008

湖南省自然科学基金（06JJ50118）； 湖南省教育厅重点科研基金（04A006）资助项目；

本校为其他机构

量子纯态和混合态是量子信息中最重要的两种量子态,是研究密度算符、量子纠缠态和量子消相干的基础.量子纯态与混合态具有本质区别.量子干涉的一个最重要的特征是量子纯态的相对位相有可以观测的效应.利用量子力学的方法,通过测定特定力学量(σ)z,(σ)x和(σ)n的取值来分析从纯态到混合态的转变.结果表明:量子纯态中的测量是各向异性的,而对于混合态则是各向同性的.

The quantum pure state and mixed state are the most important quantum states in quantum information. They are the foundation of studying density operator, quantum entanglement and quantum decoherence. The two states＇ definition and innate differences are given in quantum theory. The observable effect for quantum pure states＇ mutually phase is the most important characteristics in quantum interference. The transformation from quantum pure state to mixed state is analyzed through measurement of mechanic quantity σ^z, σ^x and σ^n by quantum m...