中子非弹性散射测量自旋团簇材料中的量子关联

项目名称： 中子非弹性散射测量自旋团簇材料中的量子关联

项目编号： No.11305150

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 刘本琼

作者单位： 中国工程物理研究院核物理与化学研究所

项目金额： 22万元

中文摘要： 自旋团簇材料包括自旋链、自旋面，以及中间维度自旋梯等低维体系是当前凝聚态物理学中的一大研究热点，不仅因为它们在高温超导物理学中显得极为重要，还因为它们是实现量子计算和组建量子计算机的候选者，在量子通讯领域有很大的应用价值。本课题主要研究自旋团簇材料中的量子关联（量子纠缠、量子失谐）随交换耦合强度、单轴各向异性场以及温度等物理参数的变化情况。对影响量子关联的关键因素进行调控，以期保持或提高体系中的量子关联，为量子信息处理提供理论依据，并对可能存在的量子临界现象进行分析。在实验方面，建立起中子非弹性散射强度与自旋-自旋关联函数之间的转换关系，设计和开展中子非弹性散射实验，测量自旋团簇材料的自旋波色散关系，进而获得任意自旋对之间的量子关联。这一技术将为实验上探测量子关联提供新的研究手段，与量子层析术和液态核磁共振这两种传统实验方案相比，中子非弹性散射技术在研究体系的量子位数上具有不可比拟的优势。

中文关键词： 量子关联；自旋团簇；非弹性中子散射；；

英文摘要： Spin-cluster materials have attracted much interest in condesed matter physics; specific examples of such low demensional systems include spin chains, planes,and intermediate dimensional spin ladders. This is not only because they play an important role in high temperature superconductors, but also they are candidates for the realizition of quantum computing and quantum computers. In this program, the effects of exchange coupling constant, uniaxial anisotropy field and temperature on the behavior of quantum correlations (quantum entanglement and quantum discord) in spin-cluster materials will be studied, in order to achieve the quantum correlations' protection and enhancement. Possible quantum critical phenomenon will be analyzed. Experimentally, inelastic neutron scattering measurements will be performed so as to obtain the spin-wave dipersion relations of the spin-cluster materials. According to the relationship between scattering intensity and spin-spin correlation functions, quantum correlations between any spin pairs can be obtained. This allows one to indirectly measure quantum correlations through neutron scattering experiments. Compared with quantum state tomography and nuclear magnetic resonance, inelastic neutron scattering technology has the great advantage in dealing with large quantum systems.

英文关键词： quantum correlations；spin cluster；inelastic neutron scattering；；