报告题目：Natural orbitals renormalization group approach to quantum-impurity systems
报告人：卢仲毅 教授
报告时间：10月16日 上午9:00—11:00
报告地点：龙赛理科搂北楼311
报告人简介：
卢仲毅，中国人民大学物理系教授。2007年获国家杰出青年基金资助，2015年获教育部自然科学一等奖，同年获中国物理学会叶企孙物理奖，2017年获得吴玉章优秀科研奖，2019年获得国家自然科学奖二等奖。主要从事凝聚态物质的电子结构研究和计算方法发展，在铁基超导和量子多体理论等研究方面取得了一批有原创性的成果：提出了铁基超导的反铁磁超交换作用机理，正确预言了母体的反铁磁半金属特性，确认了FeTe和K2Fe3Se4的反铁磁长程序及电子结构；明确了铁磁金属层中量子阱态的共振隧穿等输运性质；提出了自然轨道重整化群方法，并应用于多自由度的量子杂质系统研究；用多体场论方法研究了几种自旋链系统的奇异特性。
报告简介：
One of the most important and accurate approaches for studying interacting many-electron correlated systems is the quantum renormalization group (RG) procedure, upon which we propose a new concept in the framework of natural orbitals so that we can generalize the RG into general orbital space, namely natural orbitals renormalization group (NORG). We show that the NORG takes a polynomial (O(N3bath )) rather than exponential computational cost in the number of electron bath sites to solve low-energy eigenstates of a quantum impurity model. Moreover, the NORG can work on a quantum impurity model with any lattice topological structure. Actually, the effectiveness of the NORG is basically irrespective of a model’s topological structure. Thus, the NORG is naturally appropriate for studying quantum cluster-impurity model. This makes the NORG be a natural impurity solver to dynamical mean field theory.