Chiral surface states from 3D Landau bands
In a collaboration with the group of Philip J. W. Moll (MPI Hamburg), Mark H Fischer and Titus Neupert have studied the enhanced surface conduction in the quantum limit of the 3D semimetal bismuth. In particular, the researchers found an increase in conductivity as material is removed by a focused ion beam, a finding contrasting the intuitive expectation. Three-dimensional chiral surface states – 3D analogues of the well-known quantum Hall states in 2D – naturally account for the observed increase. The researchers' results, published in the journal Nature Physics, introduce a new approach for utilizing chiral conduction on the surfaces of 3D materials, offering a host of design options lacking in two-dimensional systems.
DOI: https://doi.org/10.1038/s41567-025-03146-7
The figure shows the Surface spectral function of a Bi slab in a strong magnetic field, the inset scanning electron microscopy images of a microstructured bismuth.
