Spin Current Experiments

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 [3,4]. 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 [1-4]. 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 [5,7].

In the talk, I will give an overview over our recent experiments on spin current transport in ferromagnet/normal metal hybrid devices [4-7]. After an introduction to pure spin current transport and spin Hall physics, I will in particular address spin pumping experiments, and discuss spin Hall magnetoresistance measurements in different materials and in nano­structures.

References

• [1] O. Mosendz et al., Phys. Rev. Lett. 104, 046601 (2010).
• [2] F. D. Czeschka et al., Phys. Rev. Lett. 107, 046601 (2011).
• [3] K. Uchida et al., Appl. Phys. Lett. 97, 172505 (2010).
• [4] M. Weiler et al., Phys. Rev. Lett. 108, 106602 (2012).
• [5] H. Nakayama et al., Phys. Rev. Lett. 110, 206601 (2013).
• [6] S. T. B. Goennenwein et al., Appl. Phys. Lett. 107, 172405 (2015).
• [7] K. Ganzhorn et al., Phys. Rev. B 94, 094401 (2016).