Every bond is ferromagnetic (+J) with probability 1−p and antiferromagnetic (−J) with probability p. p = 0 gives an ordinary Ising ferromagnet; p = 0.5 gives the fully disordered Edwards–Anderson spin glass. Dragging p live lets you watch frustration and the order parameter q appear as disorder is switched on.
H = −Σ Jij si sj
A Metropolis Monte Carlo sweep flips a randomly chosen spin whenever ΔE ≤ 0, or with probability exp(−ΔE/T) otherwise. Click or drag on the lattice to flip individual spins by hand.