We present finite-temperature Monte Carlo studies of a 2D random-anisotropy (RA) magnet on lattices containing one million spins. The correlated spin-glass state predicted by analytical theories is reproduced in simulations, as are the field-cooled and zero-field-cooled magnetization curves observed in experiments. The orientations of lattice spins begin to freeze when the temperature is lowered. The freezing transition is due to the energy barriers generated by the RA rather than due to random interactions in conventional spin-glasses. We describe freezing by introducing the time-dependent spin-glass order parameterqand the spin-melting timeτMdefined viaq=τM/tabove freezing, wheretis the time of the experiment represented by the number of Monte Carlo steps.
Keywords: freezing; random anisotropy; random magnet; spin glass; static disorder.
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