Investigating Quantum Quasiparticle Interference on the surface of Weyl Semimetal by Scanning Tunneling Microscopy*

We report work in progress for measurements of atomic structure and quantum quasiparticle interference (QPI) on the surface of Weyl semimetal (TaAs) using a low temperature scanning tunneling microscopy/spectroscopy equipped with vector magnets. The sample surface that is being studied is prepared by UHV in situ cleavage. Ta- and As- terminated surfaces are observed with atomic scale. QPI patterns that arise from quasiparticle scattering of the surface states including the topological Fermi arcs in TaAs are observed on As- and Ta- terminated surfaces respectively and compared without/with external magnetic field. The electron scattering near the atomic steps are also investigated. The results should help us to understand the electron scattering behaviors of the topological Fermi arcs of the Weyl semimetal, more comprehensively.