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TT: Fachverband Tiefe Temperaturen

TT 14: Correlated Electrons: Low-Dimensional Systems - Models 2

TT 14.8: Talk

Monday, March 11, 2013, 17:00–17:15, H9

Quantum spin models from π fluxes in correlated quantum spin hall insulators. — •Martin Bercx, Martin Hohenadler, and Fakher F. Assaad — Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany

We analyze the signatures of π fluxes in quantum spin hall insulators. We have shown in a recent work [1] that in the presence of repulsive electronic interactions each π flux gives rise to a Kramers doublet of spinon states. Free spinon states show up in a Curie law behaviour of the magnetic susceptibility. The interaction between spinon states is mediated by a bosonic mode which can be tuned with the electron-electron interaction. This has opened the possibilty to study models of interacting spin 1/2 magnetic moments hosted in the gap of a topological insulator. These effective quantum spin models can be simulated numerically with the quantum Monte Carlo method. In this contribution we present results for spin chains, spin ladders and for various other geometries.
[1] F. F. Assaad, M. Bercx, and M. Hohenadler, arXiv:1204.4728 (2012)