6533b7d9fe1ef96bd126cbb5

RESEARCH PRODUCT

Computer simulation of models for orientational glasses

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Abstract Monte Carlo studies of two- and three-dimensional lattice models where quadrupoles interact with a nearest-neighbor Gaussian coupling are reviewed. None of these models has a thermodynamic glass phase transition at non-zero temperature like the Ising spin glass: rather, phase transitions at zero temperature occur that exhibit a dynamical freeze-in spread out over a wide temperature range and are characterized by a strongly non-exponential relaxation. The time-dependent glass order parameter, q(t), decays with time, t, compatible with a stretched exponential decay q(t) ∼ exp [− (t/τ)y] with a strongly temperature-dependent exponent. While the static glass ‘susceptibility’ for isotropic orientational glasses diverges as xG ∼ T−γ0 as T → 0, for the three-dimensional three-state Potts glass an exponential divergence is found, 1n xG ∼ T−2, implying that the system is at its lower critical dimension.