Figure 2: Power laws and minima in the normal-state resistivity ρ(T).

(a) ρ(T) for crystals A–F, together with power-law fits ρ∝T^α (black lines, fitting range 1.5T_min<T<300 K). T_min corresponds to the minimum in ρ(T) for T>T_pk. (b) ρ(T) plotted on a semi-logarithmic scale for crystals A and F: ρ_F≈10⁵ρ_A as T→T_pk. (c) Evolution of T_min with ρ(300 K), which is a measure of the disorder in each crystal. The horizontal shading indicates the estimated⁶ single-particle dimensional crossover temperature T_x∼104 K, obtained using , where W is the conduction bandwidth (Supplementary Note I), and K_ρ=3/2. No anomaly is visible in ρ(T) at T_x, suggesting either that T_x may be further renormalized due to competing charge instabilities⁸, or that signatures of Tomonaga–Luttinger liquid behaviour may persist even for T<T_x (ref. 6).