Anderson Localization in 1D Disorder

All eigenstates localize exponentially in 1D random potentials — the localization length ξ ~ 1/disorder²

Loc. length ξ
Lyapunov γ = 1/ξ
IPR (inverse part. ratio)
1.00
0.00
300
|ψ|²

Anderson (1958): in 1D, any amount of uncorrelated disorder localizes all quantum eigenstates. The wavefunction decays as |ψ(x)| ~ exp(-|x-x₀|/ξ) where ξ ~ (E²-4)·(12/W²)⁻¹ near band center. Transfer matrix method computes exact localization length via Lyapunov exponent.