TY - JOUR
T1 - Observation of the quantum spin Hall effect up to 100 kelvin in a monolayer crystal
AU - Wu, Sanfeng
AU - Fatemi, Valla
AU - Gibson, Quinn D.
AU - Watanabe, Kenji
AU - Taniguchi, Takashi
AU - Cava, Robert J.
AU - Jarillo-Herrero, Pablo
N1 - Funding Information:
We thank L. Fu and X. Qian for helpful discussions. This work was partly supported through Air Force Research Laboratory grant no. FA9550-16-1-0382 as well as the Gordon and Betty Moore Foundation’s Emergent Phenomena in Quantum Systems (EPiQS) Initiative through grant no. GBMF4541 to P.J.-H. Device nanofabrication was partly supported by the Center for Excitonics, an Energy Frontier Research Center funded by the U.S. Department of Energy, Basic Energy Sciences Office, under award no. DE-SC0001088. This work made use of the Materials Research Science and Engineering Center’s shared experimental facilities supported by the NSF under award no. DMR-0819762. Sample fabrication was performed in part at the Harvard Center for Nanoscale Science supported by the NSF under grant no. ECS-0335765. S.W. acknowledges the support of the MIT Pappalardo Fellowship in Physics. The WTe2 crystal growth performed at Princeton University was supported by the NSF Materials Research Science and Engineering Center (MRSEC) grant DMR-1420541. Growth of hexagonal boron nitride crystals was supported by the Elemental Strategy Initiative conducted by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan; and the Japan Society for the Promotion of Science (JSPS) Grants-in-Aid for Scientific Research (KAKENHI) through grant nos. JP15K21722 and JP25106006. The data presented in this paper are available from the corresponding authors upon reasonable request.
PY - 2018/1/5
Y1 - 2018/1/5
N2 - A variety of monolayer crystals have been proposed to be two-dimensional topological insulators exhibiting the quantum spin Hall effect (QSHE), possibly even at high temperatures. Here we report the observation of the QSHE in monolayer tungsten ditelluride (WTe2) at temperatures up to 100 kelvin. In the short-edge limit, the monolayer exhibits the hallmark transport conductance, ∼e2/h per edge, where e is the electron charge and h is Planck's constant. Moreover, a magnetic field suppresses the conductance, and the observed Zeeman-type gap indicates the existence of a Kramers degenerate point and the importance of time-reversal symmetry for protection from elastic backscattering. Our results establish the QSHE at temperatures much higher than in semiconductor heterostructures and allow for exploring topological phases in atomically thin crystals.
AB - A variety of monolayer crystals have been proposed to be two-dimensional topological insulators exhibiting the quantum spin Hall effect (QSHE), possibly even at high temperatures. Here we report the observation of the QSHE in monolayer tungsten ditelluride (WTe2) at temperatures up to 100 kelvin. In the short-edge limit, the monolayer exhibits the hallmark transport conductance, ∼e2/h per edge, where e is the electron charge and h is Planck's constant. Moreover, a magnetic field suppresses the conductance, and the observed Zeeman-type gap indicates the existence of a Kramers degenerate point and the importance of time-reversal symmetry for protection from elastic backscattering. Our results establish the QSHE at temperatures much higher than in semiconductor heterostructures and allow for exploring topological phases in atomically thin crystals.
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U2 - 10.1126/science.aan6003
DO - 10.1126/science.aan6003
M3 - Article
C2 - 29302010
AN - SCOPUS:85040122369
SN - 0036-8075
VL - 359
SP - 76
EP - 79
JO - Science
JF - Science
IS - 6371
ER -