Strongly enhanced spin current in topological insulator/ferromagnetic metal heterostructures by spin pumping

Journal Article · Thu May 07 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4918631· OSTI ID:22410072

Wu, C. N.; Hung, H. Y.; Lin, H. Y.; Lin, P. H.; Lin, Y. H.; Fanchiang, Y. T.; Lin, J. G. ^[1]; Lee, S. F. ^[2]

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1. Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan (China)
2. Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China)

Spin pumping effect in Bi{sub 2}Se{sub 3}/Fe{sub 3}Si and Fe/Bi{sub 2}Te{sub 3} heterostructures was studied. High quality films of Bi{sub 2}Se{sub 3}(001) on ferromagnetic Fe{sub 3}Si(111) layer and Fe(111) films on Bi{sub 2}Te{sub 3}(001) layer were grown epitaxially by molecular beam epitaxy. Using a microwave cavity source, large voltages due to the Inverse Spin Hall Effect (V{sub ISHE}) were detected in Bi{sub 2}Se{sub 3}(001)/Fe{sub 3}Si(111) bi-layer at room temperature. V{sub ISHE} of up to 63.4 ± 4.0 μV at 100 mW microwave power (P{sub MW}) was observed. In addition, Fe(111)/Bi{sub 2}Te{sub 3}(001) bi-layer also showed a large V{sub ISHE} of 3.0 ± 0.1 μV at P{sub MW} of 25 mW. V{sub ISHE} of both structures showed microwave linear power dependence in accordance with the theoretical model of spin pumping. The spin Hall angle was calculated to be 0.0053 ± 0.002 in Bi{sub 2}Se{sub 3} and was estimated to be 0.0068 ± 0.003 in Bi{sub 2}Te{sub 3}. The charge current density (J{sub c}) of Bi{sub 2}Se{sub 3}/Fe{sub 3}Si and Fe/Bi{sub 2}Te{sub 3} structures are comparable and are about 2–5 times higher than the Fe{sub 3}Si/normal metal and Fe{sub 3}Si/GaAs results. The significant enhancement of spin current in topological insulator/ferromagnetic metal (TI/FM) and FM/TI bilayers is attributed to strong spin-orbit coupling inherent of TIs and demonstrates the high potential of exploiting TI-based structures for spintronic applications.

• OSTI ID: 22410072
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BISMUTH SELENIDES
BISMUTH TELLURIDES
COMPARATIVE EVALUATIONS
CRITICAL CURRENT
CURRENT DENSITY
FILMS
GALLIUM ARSENIDES
HALL EFFECT
HETEROJUNCTIONS
IRON
IRON SILICIDES
LAYERS
L-S COUPLING
MICROWAVE RADIATION
MOLECULAR BEAM EPITAXY
POTENTIALS
SPIN
TITANIUM SULFIDES