Spin injection and helicity control of surface spin photocurrent in a three dimensional topological insulator

Yuqing Huang, Y. X. Song, S. M. Wang, Irina A. Buyanova, Weimin M. Chen
Published in Published in Nature Comm., 2017, doi:10.1038/ncomms15401

A three-dimensional (3D) topological insulator (TI) is a unique quantum phase of matter with exotic physical properties and promising spintronic applications. However, surface spin current in a common 3D TI remains difficult to control and the out-of-plane spin texture is largely unexplored. Here, by means of surface spin photocurrent in Bi2Te3 TI devices driven by circular polarized light, we identify the subtle effect of the spin texture of the topological surface state including the hexagonal warping term on the surface current. By exploring the out-of-plane spin texture, we demonstrate spin injection from GaAs to TI and its significant contribution to the surface current, which can be manipulated by an external magnetic field. These discoveries pave the way to not only intriguing new physics but also enriched spin functionalities by integrating TI with conventional semiconductors, such that spin-enabled optoelectronic devices may be fabricated in such hybrid structures.

 Media interest:

“Spinning electrons open the door to future hybrid electronics”, by Karin Söderlund Leifler, LiU Nyheter, 2017-06-30

“Spinning electrons open the door to future hybrid electronics”, Phys.org, June 30 2017

“Spinning electrons open the door to future hybrid electronics”, Science Daily, June 30 2017 

“Researchers manage to generate and manipulate the surface spin current in topological insulators”, Spintronics-info, July 1 2017

“Elektroners spinn öppnar upp för framtida hybridelektronik”, SwedNanoTech Nyhetsbrev Nr.6 augusti 2017

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