Fig. 2: Non-Fermi liquid to Fermi liquid crossover and scale invariance in thermodynamic quantities.
From: Quantum-critical scale invariance in a transition metal alloy
a Temperature dependence of magnetic susceptibility for Ba(Fe1/3Co1/3Ni1/3)2As2 (B ∥ ab). Inset: 1/χ as a function of T1/3 at low temperatures. b Electronic specific heat Ce/T = (Ctot − Csch − Cph)/T for Ba(Fe1/3Co1/3Ni1/3)2As2 under several fields parallel to ab-plane. Inset: log–log plot for Ce/T vs T for B = 0 T. The dashed line emphasizes the T−0.25-power law behavior observed <1 K. c Temperature-magnetic field scale invariance in magnetization and d specific heat. The measured magnetization and specific heat collapse onto universal scaling curves in the forms of −dM/dT = B−1/3fM(T/B) and ΔCe/T = B−1/3gC(T/B), respectively, indicating the presence of the underlying free energy given by a universal function of T/B and the existence of the quantum critical point located at T = 0 and B = 0. Black lines represent scaling functions fM(T/B) for magnetization and gC(T/B) for specific heat derived from the underlying free energy, described in the main text.
