In-plane magnetic field driven conductance modulations in topological insulator kinks

TL;DR

This study investigates how in-plane magnetic fields modulate conductance in topological insulator kinks, revealing orbital effects and phase coherence influences on surface state transport through combined experiments and simulations.

Contribution

It demonstrates magnetic field-driven conductance modulation in topological insulator kinks, supported by experimental data and quantum transport simulations, highlighting orbital effects and phase coherence.

Findings

Conductance depends on in-plane magnetic field orientation.

Orbital effects trap topological surface states on kink facets.

Phase coherence influences conductance modulation patterns.

Abstract

We present low-temperature magnetoconductance measurements on Bi$_{1.5}$Sb$_{0.5}$Te$_{1.8}$Se$_{1.2}$ kinks with ribbon-shaped legs. The conductance displays a clear dependence on the in-plane magnetic field orientation. The conductance modulation is consistent with orbital effect-driven trapping of the topological surface states on different side facets of the legs of the kink, which affects their transmission across the kink. This magnetic field-driven trapping and conductance pattern can be explained with a semiclassical picture and is supported by quantum transport simulations. The interpretation is corroborated by varying the angle of the kink and analyzing the temperature dependence of the observed magnetoconductance pattern, indicating the importance of phase coherence along the cross section perimeter of the kink legs.