SKM 2023 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 23: Kagome Systems
TT 23.6: Vortrag
Dienstag, 28. März 2023, 10:45–11:00, HSZ 304
Z2 topological insulator and Hubbard interactions on the Kagome lattice — Irakli Titvinidze1, •Julian Legendre2,3, Maarten Grothus1, Bernhard Irsigler1, Karyn Le Hur2, and Walter Hofstetter1 — 1Institut für Theoretische Physik, Goethe-Universität, 60438 Frankfurt am Main, Germany — 2CPHT, CNRS, Institut Polytechnique de Paris, Route de Saclay, 91128 Palaiseau, France — 3Department of Physics and Materials Science, University of Luxembourg, 1511 Luxembourg, Luxembourg
The study of topological phase transitions has been a very active field of research since the 80’s; in recent decades topological insulators have been one of the major foci in this field. Understanding the role of the interactions in such systems is also currently is major challenge for the scientific community. In this talk, I will present a study of a time-reversal invariant topological model, with Hubbard interactions, on the Kagome lattice. The topological model contains intrinsic and Rashba spin-orbit coupling terms and position-dependent onsite energies. Relying on several analytical methods, I will show how the Z2 topological phase, resulting from the flux term, is tuned by varying the amplitude(s) of on-site energy terms and/or of the Rashba spin-orbit coupling term, at filling n = 2/3. Then, we will study the effect of Hubbard interactions on the topological properties for a specific on-site energy configuration and at vanishing Rashba spin-orbit coupling. We will use perturbation theory in the large Hubbard amplitude U limit and a mean-field method for smaller U. I will compare these analytical results with numerical results obtained by our collaborators.