Giant Spin Transfer Torque in Atomically Thin Magnetic Bilayers  

作　　者：Weihao Cao Matisse Wei-Yuan Tu Jiang Xiao Wang Yao 曹伟豪;涂维元;肖江;姚望(Department of Physics,University of Hong Kong,Hong Kong,China;Department of Physics,University of California San Diego,La Jolla,CA 92093-0319,USA;HKU-UCAS Joint Institute of Theoretical and Computational Physics at Hong Kong,Hong Kong,China;Department of Physics and State Key Laboratory of Surface Physics,Fudan University,Shanghai 200433,China;Institute for Nanoelectronics Devices and Quantum Computing,Fudan University,Shanghai 200433,China)

机构地区：[1]Department of Physics,University of Hong Kong,Hong Kong,China [2]Department of Physics,University of California San Diego,La Jolla,CA 92093-0319,USA [3]HKU-UCAS Joint Institute of Theoretical and Computational Physics at Hong Kong,Hong Kong,China [4]Department of Physics and State Key Laboratory of Surface Physics,Fudan University,Shanghai 200433,China [5]Institute for Nanoelectronics Devices and Quantum Computing,Fudan University,Shanghai 200433,China

出　　处：《Chinese Physics Letters》2020年第10期68-75,共8页中国物理快报（英文版）

基　　金：Supported by the Research Grants Council of Hong Kong(Grant Nos.HKU17303518 and C7036-17W);the University of Hong Kong(Seed Funding for Strategic Interdisciplinary Research)

摘　　要：In cavity quantum electrodynamics,the multiple reflections of a photon between two mirrors defining a cavity is exploited to enhance the light-coupling of an intra-cavity atom.We show that this paradigm for enhancing the interaction of a flying particle with a localized object can be generalized to spintronics based on van der Waals 2D magnets.Upon tunneling through a magnetic bilayer,we find that the spin transfer torques per electron incidence can become orders of magnitude larger thanℏ/2,made possible by electron's multi-reflection path through the ferromagnetic monolayers as an intermediate of their angular momentum transfer.Over a broad energy range around the tunneling resonances,the damping-like spin transfer torque per electron tunneling features a universal value of(ℏ/2)tan(θ/2),depending only on the angleθbetween the magnetizations.These findings expand the scope of magnetization manipulations for high-performance and high-density storage based on van der Waals magnets.

关 键 词：TUNNELING MAGNETIZATION MAGNETS 

分 类 号：O413.2[理学—理论物理]