TY - JOUR
T1 - Surface-State-Dominated Spin-Charge Current Conversion in Topological-Insulator-Ferromagnetic-Insulator Heterostructures
AU - Wang, Hailong
AU - Kally, James
AU - Lee, Joon Sue
AU - Liu, Tao
AU - Chang, Houchen
AU - Hickey, Danielle Reifsnyder
AU - Mkhoyan, K. Andre
AU - Wu, Mingzhong
AU - Richardella, Anthony
AU - Samarth, Nitin
N1 - Funding Information:
The work at Penn State, Colorado State, and University of Minnesota is supported by the Center for Spintronic Materials, Interfaces, and Novel Architectures (C-SPIN), a funded center of STARnet, a Semiconductor Research Corporation (SRC) program sponsored by MARCO and DARPA. N.S. and A.R. acknowledge additional support from ONR- N00014-15-1-2364. T.L., H.C., and M.W. acknowledge additional support from NSF-ECCS-1231598 and ARO-W911NF-14-1-0501. This work utilized (1) the College of Science and Engineering (CSE) Characterization Facility, University of Minnesota (UM), supported in part by NSF through the UMN MRSEC program (No. DMR-1420013); and (2) the CSE Minnesota Nano Center, UM, supported in part by NSF through the NNIN program.
Publisher Copyright:
© 2016 American Physical Society.
PY - 2016/8/11
Y1 - 2016/8/11
N2 - We report the observation of ferromagnetic resonance-driven spin pumping signals at room temperature in three-dimensional topological insulator thin films - Bi2Se3 and (Bi,Sb)2Te3 - deposited by molecular beam epitaxy on Y3Fe5O12 thin films. By systematically varying the Bi2Se3 film thickness, we show that the spin-charge conversion efficiency, characterized by the inverse Rashba-Edelstein effect length (λIREE), increases dramatically as the film thickness is increased from two quintuple layers, saturating above six quintuple layers. This suggests a dominant role of surface states in spin and charge interconversion in topological-insulator-ferromagnet heterostructures. Our conclusion is further corroborated by studying a series of Y3Fe5O12/(Bi,Sb)2Te3 heterostructures. Finally, we use the ferromagnetic resonance linewidth broadening and the inverse Rashba-Edelstein signals to determine the effective interfacial spin mixing conductance and λIREE.
AB - We report the observation of ferromagnetic resonance-driven spin pumping signals at room temperature in three-dimensional topological insulator thin films - Bi2Se3 and (Bi,Sb)2Te3 - deposited by molecular beam epitaxy on Y3Fe5O12 thin films. By systematically varying the Bi2Se3 film thickness, we show that the spin-charge conversion efficiency, characterized by the inverse Rashba-Edelstein effect length (λIREE), increases dramatically as the film thickness is increased from two quintuple layers, saturating above six quintuple layers. This suggests a dominant role of surface states in spin and charge interconversion in topological-insulator-ferromagnet heterostructures. Our conclusion is further corroborated by studying a series of Y3Fe5O12/(Bi,Sb)2Te3 heterostructures. Finally, we use the ferromagnetic resonance linewidth broadening and the inverse Rashba-Edelstein signals to determine the effective interfacial spin mixing conductance and λIREE.
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U2 - 10.1103/PhysRevLett.117.076601
DO - 10.1103/PhysRevLett.117.076601
M3 - Article
C2 - 27563980
AN - SCOPUS:84982182325
SN - 0031-9007
VL - 117
JO - Physical Review Letters
JF - Physical Review Letters
IS - 7
M1 - 076601
ER -