Anisotropic Shubnikov-de Haas effect in topological Weyl semimetal MoTe2

Newly emergent type-II Weyl semimetals with topological surface states so-called Fermi arcs have attracted much attention for their novel physical properties and potential application in quantum devices. Here, we investigate the in-plane anisotropic structure and inversion symmetry breaking by angle-resolved polarized Raman and second harmonic generation and observe the anisotropic Shubnikov-de Haas effect in Weyl Semimetal MoTe2, which is only present in the b-axis (armchair chain) direction. First-principles calculation depicts the type-II Weyl points and clear topological Fermi arcs. A nontrivial π Berry's phase from Landau quantization and an extra-quantum oscillation frequency arising by Weyl orbit are obtained, which provide evidence for the existence of an anisotropic type-II Weyl state in MoTe2. This work reveals the nontrivial topological surface state of Weyl semimetal MoTe2 in both theory and experiment, providing a promising platform for unique physical properties and applications in quantum information processing.