IV) Materials calculations with dynamical mean field theory (DMFT)

First something easier......Weiss mean field theoryIsing modelĤ = J ∑ 〈ij〉s i s jLimit d → ∞ or Z → ∞; proper scaling J = J ∗ /Z⇒ Weiss mean field theory becomes exact〈s i 〉 = ∑ s i e −βJ∗ s i 〈s j 〉 /[e βJ∗ 〈s j 〉 + e −βJ∗ 〈s j 〉 ]s i =±1