学术报告预告

题目: Computational spin caloritronics

报告人: 北京师范大学 夏钶 教授

时间: 2016年3月16日(星期三)上午9:00

地点: yl23455永利官网南校区双超所211会议室

内容简要：

Magnetization dynamics can be excited and detected electrically and thermally by metal contacts, which makes it a wonderful spin energy material. The crucial parameter for ferromagnet(F)|normal metal(N) interfaces is the spin mixing conductance that governs the absorption of a transverse spin current and the spin transfer torque. However, the spin-mixing conductance is a purely nonrelativistic concept, while there is mounting evidence that spin-orbit interactions at interfaces generate additional spin-flips and spin-orbit torques. We have solved this issue by introducing an “effective” spin mixing conductance for weakly relativistic materials. First ab initio results on ferrite|metal interface indeed indicate an enhancement that can be very significant for selected crystal orientations.

Massive particles, i.e. the electrons, as well as quasi particles, i.e. magnons, can carry a thermal spin current that generates torques at the interfaces. Based on the same theoretical frame as effective mixing conductance, we compute both kind of torques for magnetic tunnel junctions from first principles in order to validate their spin transfer power efficiency, switching speed, etc.

报告人简介：夏钶，男，1997年南京大学物理系理学博士，1998–2002荷兰、美国等地大学物理系计算材料科学博士后研究助理。2002年入选中国科学院百人计划，2008国家杰出青年科学基金获得者。历任物理研究所副研究员、研究员，博士生导师，课题组长。2009年调入北京师范大学物理学系。研究方向：量子输运理论, 自旋电子学, 电子结构计算方法发展。