Sachdev-Ye-Kitaev Strange Metal

The SYK model — N Majorana fermions with all-to-all random interactions — realizes a maximally chaotic non-Fermi liquid. It saturates the Maldacena-Shenker-Stanford bound λ_L = 2πk_BT/ℏ, has no quasi-particles, and is dual to a 2D black hole via holography.

T/J = 0.20
N = 12
q = 4
Green function: G(τ) ~ (1/J)|τ|^{−2Δ} with Δ=1/q (conformal dimension)
Lyapunov exponent λ_L = 2πT/ℏ (MSB bound saturated — maximally chaotic!)
Entropy: S(T→0) = Nα₀ (extensive ground-state degeneracy — unlike BCS)