应用量子纠缠态表象研究玻色实现下自旋压缩系统的演化与退相干

项目名称： 应用量子纠缠态表象研究玻色实现下自旋压缩系统的演化与退相干

项目编号： No.11347026

项目类型： 专项基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 孟祥国

作者单位： 聊城大学

项目金额： 20万元

中文摘要： 自旋压缩比玻色压缩可实现更大程度的压缩且更易存储，还可以大大提高量子存储的保真度，因此关于自旋压缩的研究受到极大关注。另外，自旋压缩与量子纠缠有着紧密联系，对于量子信息的研究也有着重要的意义。以往的研究对象主要集中在分立自旋态的直积态方面，本项目拟采用热场动力学方法，应用量子纠缠态表象来处理玻色实现下自旋压缩系统(连续变量系统)的演化与退相干问题。研究这类自旋压缩系统在一些退相干环境中的解析演化，揭示退相干效应对自旋压缩、量子纠缠等行为的影响；探讨这类系统与环境之间的相互作用规律，寻找引起退相干的关键因素及其微观机制，以期发现抑制退相干的有效方法。这些工作不但在理论上具有重要意义，而且还可能为实验工作者实现量子信息处理中某些实际过程提供必要参考。

中文关键词： 纠缠态方法；自旋压缩；量子纠缠；Kraus算符；量子退相干

英文摘要： Spin squeezing can result in greater squeezing degree and more easily be stored than boson squeezing, and it can significantly improve the storage fidelity, so the study of spin squeezing has been attracting attention strongly. Furthermore, spin squeezing and quantum entanglement are linked tightly, which is important for studying quantum information. In previous works, all of the research subjects are the direct products of discrete spin states. However, in this present research project we try to use the thermal field dynamics theory and the entangled state representations to address evolution and decoherence of spin squeezing systems in boson realizations (the typical continuous-variable systems). We plan to study the analytical evolutions of these spin squeezing systems under some decoherence environments, and then show how the decoherence effects influence spin squeezing and quantum entanglement. Through investigating the interaction of this type of system with the environments, we want to find the key factors and the micro mechanism causing the decoherence effects, and propose the efficient ways for overcoming deocherence. This work is not only important in theory, but also provides references for experimenters realizing certain specific quantum information processing.

英文关键词： entangled state approach；spin squeezing；quantum entanglement；Kraus operator；quantum decoherence