Observation of Shubnikov-de Haas Oscillations in Large-Scale Weyl Semimetal WTe₂ Films*

Abstract

Topological Weyl semimetal WTe 2 with large-scale film form has a promising prospect for new-generation spintronic devices. However, it remains a hard task to suppress the defect states in large-scale WTe 2 films due to the chemical nature. Here we significantly improve the crystalline quality and remove the Te vacancies in WTe 2 films by post annealing. We observe the distinct Shubnikov-de Haas quantum oscillations in WTe 2 films. The nontrivial Berry phase can be revealed by Landau fan diagram analysis. The Hall mobility of WTe 2 films can reach 1245 cm 2 V −1 s −1 and 1423 cm 2 V −1 s −1 for holes and electrons with the carrier density of 5 × 10 19 cm −3 and 2 × 10 19 cm −3 , respectively. Our work provides a feasible route to obtain high-quality Weyl semimetal films for the future topological quantum device applications.