Oral: Signature of non-trivial band topology in Shubnikov–de Haas oscillations
ORAL
Abstract
We investigate the Shubnikov-de Haas (SdH) magneto-oscillations [1] in the resistivity of two-dimensional topological insulators (TIs)[2]. 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 [2]. We show that when the non-trivial topology is produced by inverted bands with “Mexican-hat” or “Camel back” shape, SdH oscillations show an anomalous beating pattern that is solely due to the non-trivial topology of the system [2]. 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.
[1] DR Candido et al., PRR 5, 043297 (2023).
[2] DR Candido, SI Erlingsson and JC Egues arXiv: 2406.08977.
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 [2]. We show that when the non-trivial topology is produced by inverted bands with “Mexican-hat” or “Camel back” shape, SdH oscillations show an anomalous beating pattern that is solely due to the non-trivial topology of the system [2]. 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.
[1] DR Candido et al., PRR 5, 043297 (2023).
[2] DR Candido, SI Erlingsson and JC Egues arXiv: 2406.08977.
*DRC acknowledges funding from the University of Iowa Fund. SIE was supported by the Reykjavik University Research Fund. JCE acknowledges funding from the National Council for Scientific and Technological Development (CNPq) Grant No. 301595/2022-4 and São Paulo Research Foundation (FAPESP), Grant 2020/00841-9.
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Presenters
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J. Carlos Egues
- University of São Paulo