PDE/Applied Math Seminar -Jingrun Chen, Dep. of Math. UCSB - A Microscopic Derivation of Spin Transfer Torque in Ferromagnetic Multilayers

Event Date: 

Friday, October 11, 2013 -
3:00pm to 4:30pm

Event Location: 

  • 4607B South Hall

Event Contact: 

Gustavo Ponce

Email: ponce@math.ucsb.edu

SPEAKER: Jingrun Chen, Dep. of Math. UCSB

TITLE: A Microscopic Derivation of Spin Transfer Torque in Ferromagnetic Multilayers

ABSTRACT: Giant magnetoresistance is a quantum mechanical magnetoresistance effect observed in thin-film structures composed of alternating ferromagnetic and non-magnetic conductive layers. For these structures, it has been observed experimentally that the existence of a spin current makes ease of magnetization reversal, known as the effect of spin transfer torque. In this talk, we will give a microscopic derivation of this effect. In the diffusive regime, this derivation gives a model with an additional term compared with the model derived from linear response theory. Physical impacts of this additional term will be discussed with numerical verification. This is a joint work with Carlos J. Garcia-Cervera (UCSB) and Xu Yang (UCSB).