DFT+DFMT Study of Doped LaNiO₂

Infinte-layer nickelates, RNiO₂ (R = La, Nd, Pr), have garnered continued interest since it was discovered they were superconducting [1] in the hopes of a better understanding of superconductivity in unconventional superconductors. Work [2] on the normal state of the undoped RNiO₂ (R = La, Nd), revealed a high temperature Curie-Weiss (CW) regime and a low tempterature Fermi Liquid (FL) regime. We perform charge self-consistent density function theory plus dynamical mean-field theory (DFT+DMFT) calculations on La_1-xSr_xNiO₂ to determine the effects of doping on the temperature phase boundaries for the the CW and FL regimes for a range of dopings, which was simulated using supercells. We find that at a certain level of doping the FL regime becomes diminished and the system continues to exhibit magnetic fluctuations down to low tempterature, which may have consequences for magnetic fluctuation induced superconductivity. Above this level of doping the system and the temperature phase boundaries begin to approach a state similar to the undoped compound.

[1] D. Li, K. Lee, Y. Wang, M. Osada, S. Crossley, H. R. Lee, Y. Cui, Y. Hikita, and H. Y. Hwang, Nature 572, 624 (2019)

[2] G. L. Pascut, L. Cosovanu, K. Haule, and K. F. Quader, Commun Phys 6, 45 (2023)