Spin Glass — Sherrington-Kirkpatrick Model

Frustration | Replica symmetry breaking | Rugged energy landscape

Parameters

Observables

Energy E
Magnetization m
Overlap q
Accept rate

About

The SK model has N spins with random Gaussian couplings Jᵢⱼ ~ N(0,J²/N). Unlike a ferromagnet, competing interactions create frustration — no configuration can satisfy all bonds simultaneously. Below Tc≈J, the system freezes into one of exponentially many metastable states. Solved exactly by Parisi (1979) via replica symmetry breaking.