Transport evidence of topological surface states in PbBi6Te10

We present the experimental realization of Dirac fermions with a π-Berry phase in PbBi6Te10, a 3D topological insulator, as observed through Shubnikov–de Haas (SdH) oscillations in electronic transport measurements. These oscillations highlight the non-trivial nature of the material's surface states. The carriers exhibit a relativistic character, with a Fermi velocity of ∼105ms−1. Their high mobility μSdH (∼ 10 × μe) and low effective mass confirm the surface origin of the topological surface states. Hall resistivity measurements reveal that PbBi6Te10 is electron-dominated. Angle-resolved photoemission spectroscopy (ARPES) displays the hexagonal warping effect near the Fermi energy. Angle-dependent magnetoresistance follows the sin2(θ) fitting, indicating the anisotropy in the Fermi surface, consistent with the ARPES measurements. These results provide a potential platform for device applications of PbBi6Te10 due to the carriers' high mobility and low effective mass.