Fig. 2: Resistivity upturn across optimal doping in Nd1−xSrxNiO2.
From: Transport phase diagram and anomalous metallicity in superconducting infinite-layer nickelates
a Magnetoresistivity isotherms ρab(H) for 0.3 K ≤T≤ 30 K with H ∣∣ c, for the specified x values. b Resistivity in the field-induced normal state (μ0H = 34 T), normalised by the minimal values \(\rho /{\rho }_{\min }\). Data for each x is vertically shifted by 0.1 for clarity. Above x = 0.17, the magnitude of each resistivity upturn is small (\(\rho /{\rho }_{\min }\lesssim\) 1%; illustrated by the coloured shadings) and neither the magnitude of the upturn nor the corresponding T0 shows any strong dependence on x. c Upper critical field μ0Hc2 extracted using the 50% ρn criterion (\({\rho }_{{{{\rm{n}}}}}\equiv {\rho }_{ab}({T}_{{{{\rm{c}}}}}^{{\prime} })\)). A small but pronounced upturn in Hc2 below 2 K is observed for all x. d Evolution of the SC dome under varying magnetic field strengths. Tc values in finite fields are inferred from isothermal field sweeps shown in a using the 50% ρn criterion (Supplementary Fig. 1). Error bars in Tc reflect the difference between the two neighbouring temperatures with ρab(μ0H) closest to 50% of ρn. At μ0H = 12.5 and 20 T, the maximal Tc remains centred around xopt ≈ 0.17.
