Anomalous conductance steps in three-dimensional topological insulator HgTe-based quantum point contacts

Abstract

We explore electrical transport through a point contact in strained HgTe, a three-dimensional topological insulator. In the absence of a magnetic field $B$, there is no quantization. However, under higher magnetic fields, we observe distinct non-integer conductance steps. Based on numerical tight-binding calculations and a phenomenological Landauer-Büttiker approach, we attribute these atypical, non-integer quantized plateaus to significant scattering effects at the point contact.

Submitted to PRR on 10/21/2024, re-submitted with minor changes to PRR on 01/14/2025. Accepted on 02/04/2025 and published in PRR on 03/11/2025. 8 pages, 7 figures

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