MoTe2: A Type-II Weyl Topological Metal

TL;DR

This paper predicts that MoTe2 is a type-II Weyl topological metal with unique surface states and strain-induced topological phase transitions, based on ab initio calculations and experimental structure data.

Contribution

It identifies MoTe2 as a type-II Weyl semimetal with specific topological features and predicts strain-driven phase transitions, expanding the understanding of topological materials.

Findings

MoTe2 hosts 4 type-II Weyl points near the Fermi level.

The material exhibits 2 observable surface Fermi arcs without strain.

Strain induces topological phase transitions in MoTe2.

Abstract

Based on the ab initio calculations, we show that MoTe2, in its low-temperature orthorhombic structure characterized by an X-ray diffraction study at 100 K, realizes 4 type-II Weyl points between the N-th and N+1-th bands, where N is the total number of valence electrons per unit cell. Other WPs and nodal lines between different other bands also appear close to the Fermi level due to a complex topological band structure. We predict a series of strain-driven topological phase transitions in this compound, opening a wide range of possible experimental realizations of different topological semimetal phases. Crucially, with no strain, the number of observable surface Fermi arcs in this material is 2 - the smallest number of arcs consistent with time-reversal symmetry.