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Spin transport in ultrafast demagnetization and terahertz emission

发布人: admin 发布时间: 2019-12-05 16:49:29 浏览: 3556 次

报告人: 袁喆 教授(北京师范大学)
报告时间:2019-12-10 15:00
报告地点:北洋园校区32教218室

报告人摘要: 

Thespin- and energy-dependent interface reflectivity of a ferromagnetic (FM) filmin contact with a nonmagnetic (NM) film is calculated using a first-principlestransport method and incorporated into the superdiffusive spin transport modelto study the femtosecond laser-induced ultrafast demagnetization of Fe|NM andNi|NM (NM= Au, Al & Pt) bilayers. By comparing the calculateddemagnetization with transparent and real interfaces, we demonstrate that thespin-dependent reflection of hot electrons has a noticeable influence on theultrafast demagnetization and the associated terahertz electromagneticradiation. In particular, a spin filtering effect is found at the Fe|NMinterface that increases the spin current injected into the NM metal, whichenhances both the resulting demagnetization and the resulting THz emission.This suggests that the THz radiation can be optimized by tailoring theinterface, indicating a very large tunability. In the last part of this talk, Iwill review the recent progress in the spintronics neuromorphic computing. 


报告人简介:

袁喆,北京师范大学物理学系教授,在清华大学物理系就读本科和研究生;获瑞典Chalmers理工大学博士学位;随后在中科院物理研究所,荷兰Twente大学,德国Mainz大学等机构工作;2015年入职北京师范大学;目前主要从事自旋类脑计算、量子自旋输运的理论与数值计算方面研究。