Electronic structure of monolayer 1T′-MoTe2 grown by molecular beam epitaxy
Shujie Tang,
Chaofan Zhang,
Chunjing Jia,
Hyejin Ryu,
Choongyu Hwang,
Makoto Hashimoto,
Donghui Lu,
Zhi Liu,
Thomas P. Devereaux,
Zhi-Xun Shen,
Sung-Kwan Mo
Affiliations
Shujie Tang
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
Chaofan Zhang
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
Chunjing Jia
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
Hyejin Ryu
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
Choongyu Hwang
Department of Physics, Pusan National University, Busan 46241, South Korea
Makoto Hashimoto
Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
Donghui Lu
Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
Zhi Liu
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
Thomas P. Devereaux
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
Zhi-Xun Shen
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
Sung-Kwan Mo
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
Monolayer transition metal dichalcogenides (TMDCs) in the 1T′ structural phase have drawn a great deal of attention due to the prediction of quantum spin Hall insulator states. The band inversion and the concomitant changes in the band topology induced by the structural distortion from 1T to 1T′ phases are well established. However, the bandgap opening due to the strong spin-orbit coupling (SOC) is only verified for 1T′-WTe2 recently and still debated for other TMDCs. Here we report a successful growth of high-quality monolayer 1T′-MoTe2 on a bilayer graphene substrate through molecular beam epitaxy. Using in situ angle-resolved photoemission spectroscopy (ARPES), we have investigated the low-energy electronic structure and Fermi surface topology. The SOC-induced breaking of the band degeneracy points between the valence and conduction bands is clearly observed by ARPES. However, the strength of SOC is found to be insufficient to open a bandgap, which makes monolayer 1T′-MoTe2 on bilayer graphene a semimetal.
