TY - JOUR
T1 - Quantum Hall effect of Dirac surface states of as-grown single crystal flakes in Sn0.02-Bi1.08Sb0.9Te2S without gate control
AU - Ichimura, Kakeru
AU - Matsushita, Stephane Yu
AU - Huynh, Kim Khuong
AU - Tanigaki, Katsumi
N1 - Funding Information:
This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), JSPS KAKENHI Grant Nos. 17K14329, 18H04471, 18H05326, 18H04304, 18H03883, 18H03858, and 19H04530, and the thermal management of CREST, JST. This work was sponsored by research grants from The Iwatani Naoji Foundation's Research Grant. S.Y.M. thanks the Tohoku University Interdepartmental Doctoral Degree Program for Multi-dimensional Materials Science Leaders for financial support. This research was partly carried out by the support of the World Premier International Research Center Initiative (WPI) from MEXT.
Publisher Copyright:
© 2019 Author(s).
PY - 2019/7/29
Y1 - 2019/7/29
N2 - The quantum spin Hall effect (QSHE) in three-dimensional topological insulators (3D-TIs) is an important hallmark of realization of ultralow dissipative electrical transport originating from nontrivial topological surface Dirac states (TSDSs). The observation of QSHE, however, had been limited at low temperatures for thin film crystals prepared by epitaxial growth or ultrathin (nanometer-level) flakes, and the finite Fermi energy tuning was required using field effect transistor (FET) construction. Here, we show that a clear observation of QSHE with a quantized level of e 2 / h can be possible for high quality single crystal flakes of Sn-(Bi,Sb)2(Te,S)3 (Sn-BSTS) prepared by an exfoliation method without any gate control under FET construction. The QSHE is observed in an extremely large sample area of millimeter square at the largest thickness of micrometer and up to the highest temperature of 20 K, which is greatly superior to those reported for other 3D-TIs so far. The accurate band picture of both top and bottom topological surface states of Sn-BSTS is determined from both the QSHE and the Shubnikov-de Hass (SdH) oscillations. High quality Sn-BSTS of 3D-TIs will effectively be used for experiments targeting on science as well as many technological applications expected in the future.
AB - The quantum spin Hall effect (QSHE) in three-dimensional topological insulators (3D-TIs) is an important hallmark of realization of ultralow dissipative electrical transport originating from nontrivial topological surface Dirac states (TSDSs). The observation of QSHE, however, had been limited at low temperatures for thin film crystals prepared by epitaxial growth or ultrathin (nanometer-level) flakes, and the finite Fermi energy tuning was required using field effect transistor (FET) construction. Here, we show that a clear observation of QSHE with a quantized level of e 2 / h can be possible for high quality single crystal flakes of Sn-(Bi,Sb)2(Te,S)3 (Sn-BSTS) prepared by an exfoliation method without any gate control under FET construction. The QSHE is observed in an extremely large sample area of millimeter square at the largest thickness of micrometer and up to the highest temperature of 20 K, which is greatly superior to those reported for other 3D-TIs so far. The accurate band picture of both top and bottom topological surface states of Sn-BSTS is determined from both the QSHE and the Shubnikov-de Hass (SdH) oscillations. High quality Sn-BSTS of 3D-TIs will effectively be used for experiments targeting on science as well as many technological applications expected in the future.
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U2 - 10.1063/1.5112120
DO - 10.1063/1.5112120
M3 - Article
AN - SCOPUS:85073888233
VL - 115
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 5
M1 - 052104
ER -