Fig. 4

Pressure dependence of charge excitations. (a) Pressure dependence of 1/ρ _⊥(dρ _⊥/dT). (b) Contour plot of 1/ρ _⊥(dρ _⊥/dT) in the pressure–temperature plane. The solid line represents the superconducting transition temperatures determined by ac susceptibility measurements¹⁵. c Pressure dependence of power law behavior of ρ _//. The power n is determined by fitting the form of ρ _// = ρ _ο + AT ⁿ to the data of ρ _// in a temperature range between superconducting transition temperature and 15 K (see Methods and Supplementary Fig. 3)