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arXiv · 1311.5344

Berezinskii-Kosterlitz-Thouless-type transitions in d=2 quantum O(2) and O(2)xO(2) nonlinear sigma models

C. A. Hooley·S. T. Carr·J. M. Fellows·J. Schmalian
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Abstract

We discuss the d=2 quantum O(2)xO(2) nonlinear sigma model as a low-energy theory of phase reconstruction near a quantum critical point. We first examine the evolution of the Berezinskii-Kosterlitz-Thouless (BKT) transition as the quantum limit is approached in the usual O(2) nonlinear sigma model. Then we go on to review results on the ground-state phase diagram of the O(2)xO(2) nonlinear sigma model, and on the behaviour of the O(2)xO(M) nonlinear sigma model with M>2 in the classical limit. Finally, we present a conjectured finite-temperature phase diagram for the quantum version of the latter model in the O(2)xO(2) case. The nature of the finite-temperature BKT-like transitions in the phase diagram is discussed, and avenues for further calculation are identified.

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C. A. Hooley, S. T. Carr, J. M. Fellows, J. Schmalian. 2013-11-21. Berezinskii-Kosterlitz-Thouless-type transitions in d=2 quantum O(2) and O(2)xO(2) nonlinear sigma models. https://doi.org/10.7566/jpscp.3.016018

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