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Nonequilibrium Critical Dynamics of the 2D XY model

Ludovic Berthier·Peter C. W. Holdsworth·Mauro Sellitto
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Abstract

The nonequilibrium critical dynamics of the 2D XY model is investigated numerically through Monte Carlo simulations and analytically in the spin-wave approximation. We focus in particular on the behaviour of the two-time response and correlation functions and show that the ageing dynamics depends on the initial conditions. The presence of critical fluctuations leads to non-trivial violations of the fluctuation-dissipation theorem apparently reminiscent of the three dimensional Edwards-Anderson spin glass model. We compute for this reason the finite-size overlap probability distribution function and find that it is related to the finite-time fluctuation-dissipation ratio obtained in the out of equilibrium dynamics, provided that the temperature is not very low.

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Ludovic Berthier, Peter C. W. Holdsworth, Mauro Sellitto. 2001-02-20. Nonequilibrium Critical Dynamics of the 2D XY model. https://doi.org/10.1088/0305-4470%2F34%2F9%2F301

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