Topological Weyl semimetal (TWS) is a metal, where low energy excitations behave like Weyl fermions of high-energy physics. It was recently shown that due to the lower symmetry of condensed matter systems, they can realize two distinct types of Weyl fermions. The type-I Weyl fermion in a metal is formed by a linear crossing of two bands at a point in the crystalline momentum space - Brillouin zone (BZ). The second type TWSs host type-II Weyl points appearing at the touching points of electron and hole pockets, which is a result of tilted linear dispersion. The type-II TWS was predicted to exist in several compounds, including WTe2. Several ARPES studies of WTe2 were reported so far, having contradictory conclusions on the topological nature of observed Fermi arcs. In this work, we report the results of spectroscopic imaging with a scanning tunneling microscope and first principle calculations, establishing a clear quasiparticle interference features of the surface states of WTe2. Our work provides a strong evidence for surface state scattering. Although the surface Fermi arcs are clearly observed, it is still difficult to prove the existence of predicted Type-II Weyl points in the bulk.
@article{arxiv.1705.11189,
title = {Quasiparticle Interference of Surface States in Type-II Weyl Semimetal WTe$_2$},
author = {Wenhan Zhang and Quansheng Wu and Lunyong Zhang and Sang-Wook Cheong and Alexey A. Soluyanov and Weida Wu},
journal= {arXiv preprint arXiv:1705.11189},
year = {2017}
}