Anderson Localization

3D tight-binding model — mobility edge & participation ratio

Parameters

Anderson (1958):
At W/t > W_c ≈ 16.5 (3D):
ALL states localized

Below W_c: mobility edge E_c
separates extended (|E|<E_c)
from localized (|E|>E_c)

PR = (Σ|ψ|⁴)⁻¹
Extended: PR ~ N
Localized: PR ~ const