"Microscopic theory of spin-orbit and spin-tranfer torques" 

Date

Feb 10, 2017

Time

11:00 AM - 1:00 PM

Speaker

Dr. Mikhail Titov

Language

en

Main Topic

Chemie

Other Topics

Chemie

Host

Prof. C. Felser; Dr. Fecher; Dr. Kreiner

Description

Spin-orbit and spin-transfer torques are competing forces that drive magnetic domains in the heavy-metal/ferromagnet bi-layers in the presence of electric current. In this talk I present a microscopic theory of both effects that is obtained from generalised Kubo formalism and avoids the notion of spin currents and spin Hall effect. In this formalism the torques are naturally related to susceptibility tensors that can be evaluated microscopically for a given model. In this talk I mainly focus on the torques arising in a heavy-metal/ferromagnet bilayers and demonstrate that spin-orbit interactions are generally responsible for a giant enhancement of spin transfer toques. Using the symmetry classification arising from the microscopic analysis I will also revise the existing classification of torques. In particular I distinguish three major spin-transfer torques in bi-layer systems. Finally I discuss the generalisations of the theory for torques in antiferromagnets and heterostructure involving Weyl semimetals and topological insulators.

Links

• MPI CPfS

Last modified: Feb 12, 2017, 8:59:44 AM