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

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 inherentmore » of TIs and demonstrates the high potential of exploiting TI-based structures for spintronic applications.« less
Authors:
; ; ; ;  [1] ; ; ;  [2] ;  [3] ;  [4]
  1. Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)
  2. Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China)
  3. Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan (China)
  4. Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China)
Publication Date:
OSTI Identifier:
22410072
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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