From local to non-local spin current transport

Date

Dec 9, 2015

Time

4:00 PM - 5:00 PM

Speaker

Dr. Sebastian T. B. Gönnenwein

Affiliation

Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften

Language

en

Main Topic

Materialien

Other Topics

Materialien, Physik

Host

Svea Fleischer

Description

A pure spin current – i.e., the directed flow of spin angular momentum – is a fascinating manifestation of spin physics in the solid state. In ferromagnet/normal metal thin film heterostructures, pure spin currents can be generated, e.g., by means of spin pumping [1,2], or via the application of thermal gradients in the so-called spin Seebeck effect [3]. An elegant scheme for detecting spin currents relies on the inverse spin Hall effect: because of spin-orbit coupling, a spin current also induces a charge current, which then can be detected using conventional electronics [1,2,3]. Furthermore, the interplay between charge and spin currents gives rise to an interesting magnetoresistance effect in magnetic insulator/normal metal heterostructures, the so-called spin Hall magnetoresistance (SMR) effect [4]. In the talk, I will start with an introduction to pure spin current transport as well as spin Hall physics. I will then address the spin Hall magnetoresistance effect from an experimentalist’s perspective, and discuss which spin transport parameters can be derived from SMR data. Last but not least, I will introduce a novel, non-local magnetoresistance effect mediated by magnon transport in magnetic insulator/normal metal nanostructures [5,6]. This magnon-mediated magnetoresistance (MMR) can be naively understood as a non-local analogue of the SMR. However, MMR and SMR exhibit qualitatively different temperature dependencies owing to the different microscopic mechanisms at work. The MMR furthermore opens intriguing perspectives for spin transport on the nanoscale.

Links

• Seminars at the IFW

Last modified: Dec 9, 2015, 9:01:14 AM