28.03.2024Quantum transport response of topological hinge modes

Experimentalists from Princeton University, in collaboration with Titus Neupert, have found evidence for quantum coherent transport along the crystal hinges of a topological quantum material. The material in question is bismuth bromide, a so-called higher-order topological insulator. The theory group of Titus Neupert had predicted the existence of such materials in 2017, with various proposed material systems probed with different experimental techniques over the past years. The common feature of such higher-order topological insulators are conducting channels on the crystal hinges which are carrying current free of dissipation. As such, they could be used in future electronics.

The present experiment, for the first time, demonstrates quantum coherent transport through such hinge modes, by demonstrating so-called Aharonov-Bohm oscillations of the conductivity in a magnetic field. While the experiment does not prove the dissipationless nature of current flow, it demonstrates that the current is clearly concentrated at the crystal hinges.

Reference:
Quantum transport response of topological hinge modes
S. Hossain et al., Nature Physics (2024)

https://www.nature.com/articles/s41567-024-02388-1