Atomic Scale Visualization of Quantum Interference on a Weyl Semimetal Surface by Scanning Tunneling Microscopy/Spectroscopy

TL;DR

This study provides the first atomic-scale visualization of quantum interference patterns on a Weyl semimetal surface, revealing surface electronic structures and scattering processes crucial for future topological electronics.

Contribution

It presents the first atomic-scale STM/STS imaging of Weyl semimetal surface states, linking experimental interference patterns with theoretical scattering mechanisms.

Findings

Observation of coherent quantum interference patterns

Mapping of surface electronic structure below and above the chemical potential

Identification of scattering channels restricted by orbital and spin textures

Abstract

Weyl semimetals may open a new era in condensed matter physics, materials science and nanotech after graphene and topological insulators. We report the first atomic scale view of the surface states of a Weyl semimetal (NbP) using scanning tunneling microscopy/spectroscopy. We observe coherent quantum interference patterns that arise from the scattering of quasiparticles near point defects on the surface. The measurements reveal the surface electronic structure both below and above the chemical potential in both real and reciprocal spaces. Moreover, the interference maps uncover the scattering processes of NbP's exotic surface states. Through comparison between experimental data and theoretical calculations, we further discover that the scattering channels are largely restricted by the orbital and/or spin texture of the surface band. The visualization of the scattering processes can help design novel transport effects and electronics on the topological surface of a Weyl semimetal.