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arXiv · 1111.0629

Quantum criticality in a dissipative (2+1)-dimensional XY model of circulating currents in high-Tc cuprates

Iver Bakken Sperstad·Einar B. Stiansen·Asle Sudbø
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Abstract

We present large-scale Monte Carlo results for the dynamical critical exponent z and the spatio-temporal two-point correlation function of a (2+1)-dimensional quantum XY model with bond dissipation, proposed to describe a quantum critical point in high-Tc cuprates near optimal doping. The phase variables of the model, originating with a parametrization of circulating currents within the CuO_2 unit cells in cuprates, are compact, {\theta_{r,\tau}} \in [-\pi,\pi>. The dynamical critical exponent is found to be z \approx 1, and the spatio-temporal correlation functions are explicitly demonstrated to be isotropic in space-imaginary time. The model thus has a fluctuation spectrum where momentum and frequency enter on equal footing, rather than having the essentially momentum-independent marginal Fermi liquid-like fluctuation spectrum previously reported for the same model.

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Iver Bakken Sperstad, Einar B. Stiansen, Asle Sudbø. 2011-11-02. Quantum criticality in a dissipative (2+1)-dimensional XY model of circulating currents in high-Tc cuprates. https://doi.org/10.1103/physrevb.84.180503

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