Nickelate superconductivity without doping at 100 GPa in PrNiO₂

The discovery of superconductivity in infinite layer nickelates [1] has raised the hope for a better understanding of superconductivity in strongly correlated systems. Dynamical vertex approximation (DΓA) successfully predicted [2] the experimental phase diagram [3]. When applying a pressure of 12 GP, the superconducting critical temperature (T_c) of PrNiO₂ further increases to over 30 K [4].

Here we show in DΓA calculations [5] that even higher T_c's are possible if the ratio bandwidth-to-interaction is increased [5]. One way to achieve this is pressure, were we find (i) good agreement with [4], (ii) a further increase of T_c at higher pressures, and (iii) that superconductivity is possible even without doping in PrNiO₂ at a pressure slightly above 100 GPa. The last is due to the self-doping effect of the electron pockets. Another promising route we [5] identified to increase the bandwidth and T_c is to move from 3d nickelates to 4d palladates.

[1] D. Li et al., Nature 573, 624 (2019).

[2] M. Kitatani et al., npj Quantum Materials 5, 59 (2020).

[3] K. Lee et al. arXiv:2203.02580

[4] N. N. Wang et al, Nature Communications 13, 4367 (2022).

[5] M. Kitatani et al., Phys. Rev. Lett. 130, 166002 (2023).