Origin and evolution of surface spin current in topological insulators
Journal article, 2018

The Dirac surface states of topological insulators offer a unique possibility for creating spin polarized charge currents due to the spin-momentum locking. Here we demonstrate that the control over the bulk and surface contribution is crucial to maximize the charge-to-spin conversion efficiency. We observe an enhancement of the spin signal due to surface-dominated spin polarization while freezin g out the bulk conductivity in semiconducting Bi1.5Sb0.5Te1.7Se1.3 below 100K. Detailed measurements up to room temperature exhibit a strong reduction of the magnetoresistance signal between 2and100K, which we attribute to the thermal excitation of bulk carriers and to the electron-phonon coupling in the surface states. The presence and dominance of this effect up to room temperature is promising for spintronic science and technology.

Author

André Dankert

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Priyamvada Bhaskar

Dmitrii Khokhriakov

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Isabel Harrysson Rodrigues

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Bogdan Karpiak

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Venkata Kamalakar Mutta

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Uppsala University

Sophie Charpentier

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Ion Garate

Université de Sherbrooke

Saroj Prasad Dash

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Physical Review B

2469-9950 (ISSN) 2469-9969 (eISSN)

Vol. 97 12 125414

Subject Categories

Materials Chemistry

Other Physics Topics

Condensed Matter Physics

DOI

10.1103/PhysRevB.97.125414

More information

Latest update

3/29/2018