应兰州大学物理学院程晨老师邀请，北京计算科学研究中心Rubem Mondaini（Assistant Professor）近日来访并作学术报告。欢迎广大师生届时参加！

题目：Giant Magnetoresistance in Hubbard chains

报告人：Rubem Mondaini（Assistant Professor）

时间：2019年9月18日上午11点

地点：格致楼4018

联系人：程晨17710649481

报告摘要：

The problem of Giant magnetoresistance, which accounts for the dramatic change of a system's transport properties upon application of a magnetic field, is well understood. Originally discovered independently by Albert Fert and Peter Grünberg (resulting in their Nobel Prize in 2007), it was shown to be more prominent in materials composed of magnetic and non-magnetic layers. Based on these results. We use numerically unbiased methods to show that the one-dimensional Hubbard model with periodically distributed on-site interactions already contains the minimal ingredients to display the phenomenon of magnetoresistance; i.e., by applying an external magnetic field, adramatic enhancement on the charge transport is achieved. We reach this conclusion based on the computation of the Drude weight and of the single-particle density of states, applying twisted boundary condition averaging to reduce finite-size effects. The known picture that describes the giant magnetoresistance, by interpreting the scattering amplitudes of parallel or antiparallel polarized currents with local magnetization, is obtained without having to resort to different entities; itinerant and localized charges are indistinguishable. We further draw conclusions based on the prospects of emulation these ideas in the context of cold atoms.

个人简介:

2006、2008和2012年分别获得里约热内卢联邦大学物理学学士、硕士和博士学位。2012年至2015年，在宾夕法尼亚州立大学和加利福尼亚大学戴维斯分校的物理系从事博士后研究，博士后期间主要合作者是Marcos Rigol教授和Richard Scalettar教授。2016年移居中国，现任北京计算科学研究中心助理教授、博士生导师。具体的物理兴趣包括理解无序材料中磁性的发生、多体系统中的输运性质、拓扑系统中的无序、孤立量子系统中的多体局域化和热化、强相互作用诱导的超导电性以及在受到含时扰动(如光辐射)的材料中出现有序态。