A Look at the Intrinsic Superconducting Phase Diagram of Infinite-Layer Nickelates*

The long search for ‘cuprate-analog’ superconductivity in nickel-based oxides has been realized in the superconducting infinite-layer nickelates.^1,2 Interestingly, the nickelates display notable distinctions experimentally from the cuprates, particularly in the ground state for non-superconducting doping values.³ Meanwhile, the strong correlation between superconductivity and the magnitude of normal state resistivity,³ along with nontrivial structural defects in this thermodynamically unstable material,⁴ hints that the established doping dependence study could be affected by extrinsic factors arising from crystalline imperfections. With new advances in sample quality, we have revisited this problem in Nd_1–xSr_xNiO₂ (x = 0~0.3) and have found several important distinctions in the phase diagram compared to our previous investigation.³ The details of the ‘intrinsic’ phase diagram, along with the optimization process of Nd_1–xSr_xNiO₂, will be discussed.

1.  V. I. Anisimov, D. Bukhvalov, & T. M. Rice, Phys. Rev. B 59, 7901 (1999).

2.  D. Li et al., Nature 572, 624 (2019).

3.  D. Li et al., Phys. Rev. Lett. 125, 27001 (2020).

4.  K. Lee et al., APL Mater. 8, 041107 (2020).