Phase Separation in a Compressible 2D Ising Model

We perform a high precision Monte Carlo study of asymptotic domain growth in a compressible two-dimensional spin-exchange Ising model with continuous particle positions and zero total magnetization, and we investigate the effects of compressibility and lattice mismatch on the late-time domain growth law, R(t) = A + Bt(n). For mismatched systems, we measure significant deviations from the theoretically expected n = 1/3 late-time growth (n = 0.224 +/- 0.004), and for a compressible model with no mismatch, we measure only a slight deviation from n = 1/3. These results strongly suggest that the current understanding of the classes of domain growth is incomplete.