TY - JOUR
T1 - Strongly Surface State Carrier-Dependent Spin–Orbit Torque in Magnetic Topological Insulators
AU - Che, Xiaoyu
AU - Pan, Quanjun
AU - Vareskic, Božo
AU - Zou, Jingyi
AU - Pan, Lei
AU - Zhang, Peng
AU - Yin, Gen
AU - Wu, Hao
AU - Shao, Qiming
AU - Deng, Peng
AU - Wang, Kang L.
N1 - Funding Information:
X.C. and Q.P. contributed equally to this work. The authors acknowledge the support from the Army Research Office Multidisciplinary University Research Initiative (MURI) accomplished under grant number W911NF-16-1-0472 and W911NF-15-1-10561. The authors are also grateful to the support by the Spins and Heat in Nanoscale Electronic Systems (SHINES), an Energy Frontier Research Center funded by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES) under award #S000686, and the National Science Foundation (DMR-1411085).
Publisher Copyright:
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/4/1
Y1 - 2020/4/1
N2 - The topological surface states (TSS) in topological insulators (TIs) can exert strong spin–orbit torque (SOT) on adjacent magnetization, offering great potential in implementing energy-efficient magnetic memory devices. However, there are large discrepancies among the reported spin Hall angle values in TIs, and its temperature dependence still remains elusive. Here, the spin Hall angle in a modulation-doped Cr-BixSb2− xTe3 (Cr-BST) film is quantitatively determined via both transport and optic approaches, where consistent results are obtained. A large spin Hall angle of ≈90 in the modulation-doped Cr-BST film is demonstrated at 2.5 K, and the spin Hall angle drastically decreases to 0.3–0.5 as the temperature increases. Moreover, by tuning the top TSS carrier concentration, a competition between the top and bottom TSS in contributing to SOT is observed. The above phenomena can account for the large discrepancies among the previously reported spin Hall angle values and reveal the unique role of TSS in generating SOT.
AB - The topological surface states (TSS) in topological insulators (TIs) can exert strong spin–orbit torque (SOT) on adjacent magnetization, offering great potential in implementing energy-efficient magnetic memory devices. However, there are large discrepancies among the reported spin Hall angle values in TIs, and its temperature dependence still remains elusive. Here, the spin Hall angle in a modulation-doped Cr-BixSb2− xTe3 (Cr-BST) film is quantitatively determined via both transport and optic approaches, where consistent results are obtained. A large spin Hall angle of ≈90 in the modulation-doped Cr-BST film is demonstrated at 2.5 K, and the spin Hall angle drastically decreases to 0.3–0.5 as the temperature increases. Moreover, by tuning the top TSS carrier concentration, a competition between the top and bottom TSS in contributing to SOT is observed. The above phenomena can account for the large discrepancies among the previously reported spin Hall angle values and reveal the unique role of TSS in generating SOT.
UR - http://www.scopus.com/inward/record.url?scp=85080141140&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85080141140&partnerID=8YFLogxK
U2 - 10.1002/adma.201907661
DO - 10.1002/adma.201907661
M3 - Article
C2 - 32108391
AN - SCOPUS:85080141140
VL - 32
JO - Advanced Materials
JF - Advanced Materials
SN - 0935-9648
IS - 16
M1 - 1907661
ER -