Extended Data Fig. 6: Temperature dependence of the upper critical fields at two pressures.
From: High-temperature superconductivity with zero resistance and strange-metal behaviour in La3Ni2O7−δ
Upper critical field of sample S1-1 measured at a, 20.5 GPa, and b, 26.6 GPa. The red and black points in both panels represent the upper critical fields determined by \({T}_{c}^{\,{0}}\) and \({T}_{c}^{\tt{onset}}\), respectively, which are determined from the construction shown in Fig. 1. The solid lines show the results of fitting with a Ginzburg-Landau model, and the green region between red and black solid lines represents the region where there is an intermediate state or a thermally activated flux flow. By fitting Hc2(T) determined from \({T}_{c}^{\,{0}}\) with a Ginzburg-Landau model, we obtained Hc2(0) of 23 T and 19 T for 20.5 GPa and 26.6 GPa, respectively. By fitting Hc2(T) determined from \({T}_{c}^{\tt{onset}}\), respective zero-temperature values of 97 T and 83 T are obtained.
