Effective spin couplings in the Mott insulator of the honeycomb lattice Hubbard model

Yang HY, Fabricio Albuquerque A, Capponi S, Laeuchli AM, Schmidt KP (2012)

Publication Status: Published

Publication Type: Journal article

Publication year: 2012

Journal

New Journal of Physics Institute of Physics: Open Access Journals / Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft

Publisher: IOP PUBLISHING LTD

Book Volume: 14

DOI: 10.1088/1367-2630/14/11/115027

Abstract

Motivated by the recent discovery of a spin-liquid phase for the Hubbard model on the honeycomb lattice at half-filling (Meng et al 2010 Nature 88 487), we apply both perturbative and non-perturbative techniques to derive effective spin Hamiltonians describing the low-energy physics of the Mottinsulating phase of the system. Exact diagonalizations of the so-derived models on small clusters are performed, in order to assess the quality of the effective low-energy theory in the spin-liquid regime. We show that six-spin interactions on the elementary loop of the honeycomb lattice are the dominant sub-leading effective couplings. A minimal spin model is shown to reproduce most of the energetic properties of the Hubbard model on the honeycomb lattice in its spin-liquid phase. Surprisingly, a more elaborate effective low-energy spin model obtained by a systematic graph expansion rather disagrees beyond a certain point with the numerical results for the Hubbard model at intermediate couplings.

Authors with CRIS profile

Kai Phillip Schmidt Professur für Theoretische Physik

Involved external institutions

Leopold-Franzens-Universität Innsbruck / University of Innsbruck AT Austria (AT) Université Fédérale de Toulouse Midi-Pyrénées FR France (FR) Universidade Federal do Rio de Janeiro (UFRJ) / Federal University of Rio de Janeiro BR Brazil (BR) École Polytechnique Fédérale de Lausanne (EPFL) CH Switzerland (CH)

How to cite

APA:

Yang, H.-Y., Fabricio Albuquerque, A., Capponi, S., Laeuchli, A.M., & Schmidt, K.P. (2012). Effective spin couplings in the Mott insulator of the honeycomb lattice Hubbard model. New Journal of Physics, 14. https://doi.org/10.1088/1367-2630/14/11/115027

MLA:

Yang, Hong-Yu, et al. "Effective spin couplings in the Mott insulator of the honeycomb lattice Hubbard model." New Journal of Physics 14 (2012).

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