Berlin 2008 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 29: Poster II

DY 29.44: Poster

Donnerstag, 28. Februar 2008, 16:00–18:00, Poster C

Quantum Monte Carlo study of the 2D quantum compass model — •Sandro Wenzel and Wolfhard Janke — Institut für Theoretische Physik, Universität Leipzig, Postfach 100 920, 04109 Leipzig

The so-called two-dimensional compass models have recently attracted interest in both the classical and quantum case due to its relevance for describing orbital interactions, arrays of superconducting Josephson junctions and as a model for protecting qubits in quantum computation [1]. Recently it was shown [2] that the classical version has a directional-ordering transition in the Ising universality class and it was proposed that this also holds for the quantum version [3–4]. Here we contribute to this question with a dedicated Quantum Monte Carlo study of the directional-ordering transition in the quantum compass model at finite temperatures. We obtain the critical temperature and the critical exponents and compare with reference [5].

[1] B. Douçot, M. V. Feigel’man, L. B. Ioffe, and A. S. Ioselevich, Phys. Rev. B 71, 024505 (2005).
[2] A. Mishra et al., Phys. Rev. Lett. 93, 207201 (2004).
[3] J. Dorier, F. Becca, and F. Mila, Phys. Rev. B 72, 024448 (2005).
[4] H.-D. Chen, C. Fang, J. Hu, and H. Yao, Phys. Rev. B 75, 144401 (2007).
[5] T. Tanaka and S. Ishihara, Phys. Rev. Lett. 98, 256402 (2007).