Dresden 2026 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 83: Topology: Quantum Hall Systems

TT 83.13: Vortrag

Donnerstag, 12. März 2026, 18:15–18:30, HSZ/0105

Quantized and nonquantized Hall response in topological Hatsugai-Kohmoto systems — •Thibaut Desort, Mark Oliver Goerbig, and Corentin Morice — Laboratoire de physique des solides, Université Paris-Saclay, Orsay, France

The Hall conductivity of insulators is well-known to be quantized, including in interacting systems [1]. The Hatsugai-Kohmoto (HK) interaction [2], a type of Hubbard model diagonal in reciprocal space, is now widely studied in the context of topology, owing to the fact that its eigenstates, eigenenergies and Green’s functions can be computed exactly. Using the Kubo formula, it is possible to access the Hall conductivity which has, even in the presence of the HK interaction, been reported to be quantized because it coincides with a Chern number [3]. In this work, using Zeeman fields, we lift the many-body degeneracy induced by the Hatsugai-Kohmoto interaction in the topological Kane-Mele model. This selects specific states within the ground-state manifold that reveal a surprising non-quantized Hall response.
[1] Q. Niu, D. J. Thouless, Y.-S. Wu, Phys. Rev. B 31, 3372 (1985)
[2] Y. Hatsugai, M. Kohmoto, J. Phys. Soc. Jap. 61, 2056 (1992)
[3] P. Mai, B. E. Feldman, P. W. Phillips, Phys. Rev. 5, 013162 (2023)

Keywords: Chern insulators; Berry curvature; Kane-Mele model; Correlated systems; Hatsugai-Kohmoto interaction