标题：Spin-orbit coupling in semiconductors
主讲人：骆军委（中国科学院半导体研究所研究员，半导体超晶格国家重点实验室副主任）
时间：2017年1月5日下午3:00
地点：综合楼0511
讲座内容：Spin-orbit coupling is a key property of semiconductors to explore spintronics without external magnetic field. It can induce spin polarization, acting like an effective magnetic field, in nonmagnetic 3D crystals when the inversion symmetry is broken, as manifested by the bulk Rashba and Dresselhaus effects. We establish that these spin-polarization effects originate fundamentally from specific atomic site asymmetries, rather than, as generally accepted, from the asymmetry of the crystal space group. This understanding leads to the recognition that a previously overlooked hidden form of spin polarization should exist in centrosymmetric crystals. Although all energy bands must be doubly degenerate in centrosymmetric materials, we find that the two components of such doubly degenerate bands could have opposite polarizations, each spatially localized on one of the two separate sectors forming the inversion partners. We demonstrate such hidden spin polarizations in particular centrosymmetric crystals by first-principles calculations. This new understanding could considerably broaden the range of currently useful spintronic materials and enable the control of spin polarization by means of operations on the atomic scale. I will also present our recent works on novel Rashbaspin-orbit coupling effects in one-dimensional nanowires.
专家简介：骆军委，中国科学院半导体研究所研究员，半导体超晶格国家重点实验室副主任，中组部青年千人计划获得者。2006年在中国科学院半导体研究所获得博士学位。2007－2014年在美国可再生能源国家实验室工作，先后担任博士后、永久职位科学家、资深科学家。2014年回国工作。研究领域为半导体物理与器件模拟, 在半导体自旋轨道耦合效应、硅基半导体信息功能材料理论设计和发展原子精度全量子力学器件模拟方法等领域开展了系统的研究，包括在Nature子刊 (4篇)、Phys. Rev. Lett. (5篇)、JACS (1篇)、IEDM(1篇)、Energy &Env. Sci. (1篇)、NanoLett. (7篇)等国际学术期刊上发表SCIE论文50余篇，被SCIE他引1000余次。多次在APS、ACS和E-MRS等国际重要会议做邀请报告和分会主席。
