Thorsten Hesjedal

Affiliations

• Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom

Title

• Spin pumping through a topological insulator studied by ferromagnetic resonance

Abstract

Topological insulators (TIs) have received widespread attention due to their large spin-orbit coupling and dissipationless, counter-propagating conduction channels in the surface state. So far, there has been only limited experimental research focused on the development of TI-FM heterostructures and similar TI devices, both for spin transport and proximity-enhancement studies [1,2]. In this work, we demonstrate the incorporation of a TI into a pseudo-spin valve heterostructure and study the time- and layer-resolved magnetodynamics [3].We use vector-network analyzer FMR and time-resolved x-ray magnetic circular dichroism [4] to demonstrate that TIs function as efficient spin sinks, while also allowing a limited dynamic coupling between ferromagnetic layers. These results shed new light on the spin dynamics of this novel materials class, and suggest future directions for the development of room temperature TI-based spintronics.

References

• [1] A. A. Baker, A. I. Figueroa, K. Kummer, L. J. Collins-McIntyre, T. Hesjedal, and G. van der Laan, Enhanced Curie temperature of Cr-doped Bi₂Se₃ thin films through the magnetic proximity effect, Phys. Rev. B, in press (2015).
• [2] L. R. Shelford, T. Hesjedal, L. Collins-McIntyre, S. S. Dhesi, F. Maccherozzi, and G. van der Laan, Electronic Structure of Fe and Co magnetic adatoms on Bi₂Ti₃ Surfaces, Phys. Rev. B 86, 081304(R) (2012).