题 目:Electron Dynamics in Slowly Varying Anti-ferromagnetic texture -- Emergent non-Abelian Electromagnetism
报告人:程然
工作单位: 美国德克萨斯大学奥斯汀分校物理系
时 间:8月10日(周五)15:30-17:00
地 点:李薰楼468会议室
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报告摘要:
Effective dynamics of conduction electrons in anti-ferromagnetic (AFM) materials with slowly varying spin texture is developed via non-Abelian gauge theory. Quite different from the ferromagnetic (FM) case, the spin of a conduction electron does not follow the background texture even in the adiabatic limit due to the accumulation of a SU(2) non-Abelian Berry phase. Correspondingly, it is found that the orbital dynamics becomes spin dependent and is affected by two emergent gauge fields. While one of them is the non-Abelian generalization of what has been discovered in FM systems, the other leads to an anomalous velocity that has no FM counterpart. An example of FM/AFM/FM tri-layer structure with experimental predictions is provided.
References:
[1] Electron dynamics in slowly varying anti-ferromagnetic texture, Ran Cheng and Qian Niu, arXiv:1201.3523
报告人介绍:
Education:
♦ University of Texas at Austin 09. 2008 – Present
Department of Physics, PhD candidate, Condensed Matter Theory
♦ Huazhong University of Science and Technology 09. 2004 – 06. 2008
Department of Physics, Bachelor of Science, GPA: 90.0/100.0
Thesis: Study of Quantum Adiabatic Theory and Geometric Phases in a Model
Current Research:
♦ Anti-ferromagnetic Spintronics
1. Electron dynamics and emergent gauge structures in smooth anti-ferromagnetic Texture
2. Spin transfer torque and spin dynamics in anti-ferromagnetic metals
3. Domain Wall dynamics and magneto-resistance
♦ Vortex dynamics in two-dimensional quantum fluid
1. Berry phase theory of quantized Magnus force
2. Vortex interaction due to the compressibility of quantum fluid