Extended Data Fig. 3: Analysis of the resistivity under pressure.
From: Strange-metal behaviour in a pure ferromagnetic Kondo lattice
a, Low-temperature ρ(T) of CeRh6Ge4 versus T2 under pressures up to 0.69 GPa. For clarity, the data at consecutive pressures are offset vertically by 0.2 μΩ cm. The low-temperature data in the magnetic state was fitted with a quadratic temperature dependence, ρ(T) = ρ0 + AT2, as shown by the solid black lines. b, The corresponding derivative dρ(T)/dT, where the position of TC was determined at each pressure from the position of the maximum, as indicated by the vertical arrows. a.u., arbitrary units. c, Low-temperature ρ(T) versus T2 of CeRh6Ge4 at pressures above the QCP; the data at consecutive pressures are offset vertically by 0.02 μΩ cm. The solid lines show the quadratic temperature dependence, indicating the occurrence of Fermi-liquid behaviour at low temperatures. d, Low-temperature enlargement of ρ(T) − ρ0 for two pressures either side of the QCP, where the data at 0.69 GPa are vertically offset by 0.02 μΩ cm. e, Resistivity as a function of temperature plotted as δρ = ρ − ρFL, for various pressures p. ρFL is the Fermi-liquid contribution to the resistivity, obtained from fitting the low-temperature ρ(T) with a quadratic temperature dependence. The deviation of δρ from zero indicates the onset of non-Fermi-liquid behaviour, and hence corresponds to TFL, as marked by the vertical arrows. f, Pressure dependence of the residual resistivity ρ0, obtained from analysing the low-temperature ρ(T) at various pressures, and where the error bars are smaller than the symbol size. This quantity reaches a maximum around the QCP.
