DFT + embedded DMFT Study of Doped Rare-Earth Nickelates

Doped rare-earth nickel-oxide compounds have continued to garner interest since they were discovered to be superconducting [1]. Among several theoretical studies, a recent advancement [2] is the proposal of a correlation-temperature phase diagram for the undoped parent compound RNiO₂ (R = La, Nd); this exhibits a high-temperature Curie-Weiss regime, a regime wherein Ni-d moments are partially screened at intermediate temperatures, and a fully screened low-temperature Fermi liquid regime as the ground state. To study the effects of doping on the phase diagram boundaries and on the electronic properties of the ground state, we perform self-consistent density functional theory (DFT) and embedded dynamical mean-field theory (eDMFT) calculations on La_1-xSr_xNiO₂, for a range of doping (x). We construct appropriate supercells for various dopings and find significant changes in the density of states for sufficiently large doping. Additionally, we examine the effects of doping on the projected band structure for the Ni-d electrons. We also discuss results from our eDMFT calculations.

1. D. Li, K. Lee, B. 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, K. F. Quader, Comm Phys 6, 45 (2023).