关联电子系统与玻色场相互作用的理论研究

项目名称： 关联电子系统与玻色场相互作用的理论研究

项目编号： No.11474200

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 郑杭

作者单位： 上海交通大学

项目金额： 70万元

中文摘要： 关联电子系统与玻色场相互作用是凝聚态物理和量子物理等研究领域中的重要科学问题。从理论研究的角度，决定这类相互作用系统物理性质的主要是两个因素：两者耦合的强度和各自的特征能量标度。在耦合强度较弱或很强以及两者能量标度相差较大的近绝热情形，理论上已有较好的处理方法。但对中间耦合强度以及非绝热情形尚缺乏相应的理论方法。本项目目标是针对中间耦合强度以及非绝热情形发展一套解析的理论研究方法，要求它在耦合强度较弱或很强以及两者能量标度相差较大的近绝热情形与已有的理论一致。由此出发研究：1、如何处理多电子系统的强关联特性导致的非绝热性及其物理效应；2、如何在超越平均场近似的基础上同时处理电子间关联及其与玻色场相互作用的互相联系和互相竞争；3、关联电子系统的电荷、自旋及轨道自由度之间的耦合以及与晶格自由度之间的相互作用问题，并计算可与实验做比较的物理量。

中文关键词： 电子结构；电子关联；过渡金属氧化物；光晶格；量子相变

英文摘要： The interaction between correlated electrons and bosonic field is an important research topic in areas of condensed state physics and quantum physics. In theoretical viewpoint, the properties of this kind of interacting systems were determined by two factors: the coupling strength between electrons and bosonic field and their own characteristic energy scales. For weak or strong coupling case and for the near adiabatic limit we already have good theory. But for intermediate coupling strength and the non-adiabatic case there is still a lack of working theoretical approach. The goal of this project is to develop an theoretical approach to study the intermediate coupling strength and non-adiabatic cases. We will study: 1. how to deal with the non-adiabaticity arising from the strongly correlated electrons; 2. how to deal with the correlation and competition between strongly correlated electrons and their interaction with bosonic fields; 3. the coupling between various degrees of freedom of correlated electrons, e.g., charge, spin, orbital, as well as the lattice phonons, and how to calculate the physical quantities which can be compared with experiments.

英文关键词： electronic state;correlation;metallic oxide;optical lattice;quantum phase transition