Affiliation
RWTH Aachen University
Talk Title
3D Quantum Hall effect in a higher order topological insulator
Abstract
We consider a model described by the Bernevig-Hughes-Zhang Hamiltonian in an external vertical magnetic field and confined to a 3D ball geometry. This model features a hinge state localized near the equator, thus being identified as a higher order topological insulator. Studying the boundary charges concentrated near the equator and around a thin vertical hole, we establish their linear dependences on the magnetic flux piercing through the hole. The linear slopes acquire universal quantised values and are identified with the Hall conductances in the radial direction. This 3D Quantum Hall effect is shown to be robust against a potential disorder.