Fermi arc electronic structure and Chern numbers in the type-II Weyl semimetal candidate Mo x W 1 − x Te 2

DOI: 10.1103/PhysRevB.94.085127

Authors: Ilya Belopolski (Princeton University) , Su-yang Xu (Princeton University) , Yukiaki Ishida (University of Tokyo) , Xingchen Pan (Nanjing University) , Peng Yu (Nanyang Technological University) , Daniel S. Sanchez (Princeton University) , Hao Zheng (Princeton University) , Madhab Neupane (Princeton University) , Nasser Alidoust (Princeton University) , Guoqing Chang (University of Singapore) , Tay-rong Chang (National Tsing Hua University) , Yun Wu (Iowa State University) , Guang Bian (Princeton University) , Shin-ming Huang (National University of Singapore; National Sun Yat-sen University) , Chi-cheng Lee (National University of Singapore) , Daixiang Mou (Iowa State University) , Lunan Huang (Iowa State University) , You Song (Nanjing University) , Baigeng Wang (Nanjing University) , Guanghou Wang (Nanjing University) , Yao-wen Yeh (Princeton University) , Nan Yao (Princeton University) , Julien E. Rault (Synchrotron SOLEIL) , Patrick Le Fèvre (Synchrotron SOLEIL) , François Bertran (Synchrotron SOLEIL) , Horng-tay Jeng (National Tsing Hua University; Institute of Physics, Academia Sinica) , Takeshi Kondo (University of Tokyo) , Adam Kaminski (Iowa State University) , Hsin Lin (National University of Singapore) , Zheng Liu (Nanyang Technological University) , Fengqi Song (Nanjing University) , Shik Shin (University of Tokyo) , M. Zahid Hasan (Princeton University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 94

State: Published (Approved)
Published: August 2016
Diamond Proposal Number(s): 13653

Abstract: It has recently been proposed that electronic band structures in crystals can give rise to a previously overlooked type of Weyl fermion, which violates Lorentz invariance and, consequently, is forbidden in particle physics. It was further predicted that MoxW1−xTe2 may realize such a type-II Weyl fermion. Here, we first show theoretically that it is crucial to access the band structure above the Fermi level ɛF to show a Weyl semimetal in MoxW1−xTe2. Then, we study MoxW1−xTe2 by pump-probe ARPES and we directly access the band structure >0.2 eV above ɛF in experiment. By comparing our results with ab initio calculations, we conclude that we directly observe the surface state containing the topological Fermi arc. We propose that a future study of MoxW1−xTe2 by pump-probe ARPES may directly pinpoint the Fermi arc. Our work sets the stage for the experimental discovery of the first type-II Weyl semimetal in MoxW1−xTe2.

Journal Keywords: Topological phases of matter; Weyl fermions; Topological materials; Transition-metal dichalcogenide; Weyl semimetal; Angle-resolved photoemission spectroscopy

Subject Areas: Physics


Instruments: I05-ARPES