Signature of non-trivial band topology in Shubnikov--de Haas oscillations

• Published in: arXiv.org 2024-06
• Main Authors: Candido, Denis R, Erlingsson, Sigurdur I, João Vitor I Costa, Egues, J Carlos
• Format: Article
• Language: English
• Subjects: Electrical resistivity; Fourier transforms; Oscillations; Spin-orbit interactions; Topological insulators; Topology
• ISSN: 2331-8422

We investigate the Shubnikov-de Haas (SdH) magneto-oscillations in the resistivity of two-dimensional topological insulators (TIs). Within the Bernevig-Hughes-Zhang (BHZ) model for TIs in the presence of a quantizing magnetic field, we obtain analytical expressions for the SdH oscillations by combining a semiclassical approach for the resistivity and a trace formula for the density of states. We show that when the non-trivial topology is produced by inverted bands with ''Mexican-hat'' shape, SdH oscillations show an anomalous beating pattern that is {\it solely} due to the non-trivial topology of the system. These beatings are robust against, and distinct from beatings originating from spin-orbit interactions. This provides a direct way to experimentally probe the non-trivial topology of 2D TIs entirely from a bulk measurement. Furthermore, the Fourier transform of the SdH oscillations as a function of the Fermi energy and quantum capacitance models allows for extracting both the topological gap and gap at zero momentum.