Extended Data Fig. 5: In-field properties of the sample with x= 0.8.
From: State with spontaneously broken time-reversal symmetry above the superconducting phase transition
(a) Temperature dependence of the specific heat measured by the relaxation method with the relative temperature increase of 2%. (b) Temperature dependence of the longitudinal electrical resistivity measured with the AC current amplitude 1 A/cm2 and the frequency 173 Hz. (c) Temperature dependence of the AC susceptibility measured with AC excitation field B = 0.3 mT and f = 777 Hz in different DC fields applied along the crystallographic c-axis. (d) Temperature dependence of the AC susceptibility measured with AC excitation field B = 0.3 mT and f = 777 Hz in zero DC field (left axis), and the DC susceptibility in B = 0.5 mT applied in the ab-plane (right axis). (e) Experimental magnetic-field phase diagram for the superconducting phase transition defined by zero resistance from the data in panel (b), and AC susceptibility from the data in panel (c), and onset temperature of the dominant specific heat anomaly shown in panel (a) [note that the resolution here is not sufficient to identify \({T}_{{{{\rm{c}}}}}^{Z2}\)]. The relative splitting between the temperatures is increased with magnetic field. (f) The low-field region of the same phase diagram as in panel (e). The displayed error bars correspond to the uncertainty in the determination of Tc.
