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Abstract
We study the dynamics of the q-state random bond Potts ferromagnet on the
square lattice at its critical point by Monte Carlo simulations with single
spin-flip dynamics. We concentrate on q=3 and q=24 and find, in both cases,
conventional, rather than activated, dynamics. We also look at the
distribution of relaxation times among different samples, finding different
results for the two q values. For q=3 the relative variance of the relaxation
time tau at the critical point is finite. However, for q=24 this appears to
diverge in the thermodynamic limit and it is ln(tau) which has a finite
relative variance. We speculate that this difference occurs because the
transition of the corresponding pure system is second order for q=3 but first
order for q=24.
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