Non-Fermi liquid transport · T-linear resistivity · Planckian dissipation
The strange metal phase (found in cuprate and heavy-fermion superconductors) violates Fermi liquid theory: instead of the conventional ρ ∝ T² arising from electron-electron scattering, it exhibits ρ = ρ₀ + AT with A remarkably universal. Planckian dissipation (Zaanen 2004): the scattering rate saturates at the quantum limit τ⁻¹ = αk_BT/ℏ with α ≈ 1, suggesting the system scatters as fast as quantum mechanics allows. No well-defined quasiparticles exist — strange metals are best understood via holography (AdS/CFT) as strongly-coupled quantum critical fluids dual to black holes.