Theoretical Study of Quasiparticle Interference in Weyl Semimetals with ab initio Band Structure Informed Tight-Binding Hamiltonian

The Weyl semimetal is a group of interesting materials where Weyl fermions emerge around singularity points of Berry curvature in the band structure (so called Weyl nodes). A direct consequence of the Weyl nodes is the anomalous surface state arising from the separation of Weyl nodes with opposite topological charges. The energy bands of the surface states cross the Fermi level and form a Fermi arc which connects the projections of Weyl nodes on the surface. Experimentally, observation of the Fermi arc is taken as a fingerprint of the Weyl semimetals. Here we theoretically study the quasiparticle interference (QPI) due to impurity scattering on surfaces in several Weyl semimetals. The scattering between Fermi arcs can lead to special patterns of QPI as indirect observation of the Fermi arcs. In particular, we adopt the accurate tight-binding multi-orbital Hamiltonian constructed from the first-principle electronic structure calculations for each material. We anticipate that our theoretical results will help interpret STM-based measurements on a more comparable footing, thus providing guidance for the identification of Weyl physics.