Probing the bulk of a magnetically doped topological insulator with gate-to-channel capacitance
Phys. Rev. B 114, 295110 – Published 12 November, 2026
DOI: https://doi.org/10.1103/8h53-d9nj
Abstract
We show that the gate-to-channel capacitance in magnetically doped topological insulators allows access to information on bulk conductivity. We found that unlike resistivity, capacitance directly reveals the presence of two different types of bulk insulators. Furthermore, the capacitance captures the different topology of the two insulators. We also found that deep on a quantized plateau, changes in the low value conductivity of the bulk remain detectable via capacitance. We conclude that the combination of capacitance and transport in Hall bars enables a comprehensive investigation of the interplay of bulk and edge effects in magnetically doped topological insulators.
