Quantum Hall effect in n-p-n and n-2D Topological Insulator-n junctions

TL;DR

This study investigates quantized transport phenomena in HgTe topological insulator junctions, revealing fractional resistance plateaux and edge state interactions under magnetic fields, advancing understanding of quantum Hall effects in topological systems.

Contribution

It introduces a simple model explaining resistance quantization in n-2D TI-n junctions and demonstrates fractional plateaux in n-p-n regimes under magnetic fields.

Findings

Fractional resistance plateau at 2h/e^2 in n-p-n regime.

Non-universal resistance plateaux in n-2D TI-n regime.

Edge state equilibration influences resistance in topological insulator junctions.

Abstract

We have studied quantized transport in HgTe wells with inverted band structure corresponding to the two-dimensional topological insulator phase (2D TI) with locally-controlled density allowing n-p-n and n-2D TI-n junctions. The resistance reveals the fractional plateau $2h/e^{2}$ in n-p-n regime in the presence of the strong perpendicular magnetic field. We found that in n-2D TI-n regime the plateaux in resistance in not universal and results from the edge state equilibration at the interface between chiral and helical edge modes. We provided the simple model describing the resistance quantization in n-2D TI-n regime.