Figure 1. Basic characteristics of type-II TWS and characterization of MoTe₂ single crystals.

(a) Schematic illustration of type-I and type-II Weyl fermions and Weyl points in the momentum space. (b) Schematic showing the Weyl points of MoTe₂ in a BZ and its projection to the k_x–k_z plane. (c) Schematic showing the Weyl points in the energy–momentum space and their projection to the k_x–E plane. (d) Illustration of the BZ of T_d-MoTe₂ with high symmetry point marked. (e) Fermi surface by our ab initio calculation, showing the bulk electron, hole pockets and the surface states (marked as SS). (f) Crystal structure of the T_d -MoTe₂, showing alternating ‘…A-B-A-B…' stacking of MoTe₂ layers. (g) Core-level spectrum showing characteristic Mo_4s, Te_4p/4d core-level peaks. Left inset: cleaved surface of MoTe₂ single crystal used in this study. Right insets: Laue and low-energy electron diffraction (LEED) pattern showing the T_d phase of MoTe₂. (h) Broad-range photoemission spectral intensity map of the Fermi surface (FS) covers >10 BZs, showing the correct symmetry and the characteristic FS.