Landau Levels in a Weyl-type Spin-orbit Coupling Band

The observation of anomalous quantum Hall and Shubnikov-de Haas (SdH) oscillation sequences, wherein Landau level energy exhibits a proportionality to the square root of the applied external magnetic field, has opened up new avenues of research into relativistic Fermions. This contrasts conventional Landau levels, where energy increases linearly with the external magnetic field. In this study, we investigate Landau levels in a novel class of topological materials characterized by Weyl-type spin-orbital coupling bands, focusing on the 2D Tellurium (Te) conduction band. Here, the Landau-level energy takes on the form E_n=nhω_c/2π±√4πneBλ²/h (n≥0), with λ representing the spin-orbit coupling parameter. By carefully tuning both the chemical potential and the magnetic field, we experimentally observed a unique Landau-level spectrum. Notably, the presence of two Fermi surfaces, distinguished by different chiralities, leads to Berry curvature flux flow from one Fermi surface to another. Our research sheds light on the distinctive Landau levels within a Weyl-type spin-orbit coupling band, exemplified by the 2D Te conduction band, and extends our understanding of topological properties to noncentrosymmetric materials with strong spin-orbit interactions.