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arXiv · 2603.24220

Topological insulator single-electron transistors for charge sensing applications

Omargeldi Atanov·Junya Feng·Jens Brede·Oliver Breunig·Yoichi Ando
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Abstract

We present topological insulator (TI)-based single-electron transistors (SETs) as magnetic-field-compatible charge sensing devices that are easily integrable with TI-superconductor hybrid platforms. We observe well-resolved Coulomb diamonds in the charge-stability diagrams of our devices confirming the charge quantization and single-electron transport. In some devices, the Coulomb resonances show persistent shifts corresponding up to $\sim$ e/2 charge. An axial magnetic field further displaces these shifts to higher or lower gate voltages. We find that the axial magnetic-field dependence of the shifts is consistent with the Zeeman shift of a trap state coupled to the SET, and we reproduce the observations using numerical simulations. The resonance shifts are therefore identified as a consequence of the sensitivity of our TI-SET devices to charges in proximity. Establishing this charge sensing capability is a first step toward integrating TI-SETs as charge sensors in more complex TI-based hybrid devices, with the overarching goal of detecting and braiding Majorana zero modes.

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Omargeldi Atanov, Junya Feng, Jens Brede, Oliver Breunig, Yoichi Ando. 2026-03-25. Topological insulator single-electron transistors for charge sensing applications. https://arxiv.org/abs/2603.24220

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