The recent discovery of superconductivity under pressure in Ruddlesden-Popper (RP) nickelates has attracted a great deal of attention. Here, using density-functional theory plus dynamical mean-field theory, we study the correlated electronic structure of the latest superconducting member of the family: the alternating single-layer bilayer nickelate La$_{ 5}$Ni$_{ 3}$O$_{ 11}$. Due to its alternating single-layer and bilayer structural motif, this hybrid RP nickelate exhibits layer-selective physics with the single-layer neighboring a Mott instability, rendering the bilayer the dominant contributor to its low-energy physics, both at ambient and high pressure. The electronic structure of La$_{ 5}$Ni$_{ 3}$O$_{ 11}$ ultimately resembles that of the bilayer compound La$_{ 3}$Ni$_{ 2}$O$_{ 7}$, pointing to the presence of universal features in the family of superconducting RP nickelates. Thus, La$_{ 5}$Ni$_{ 3}$O$_{ 11}$ provides a new platform to disentangle the key degrees of freedom underlying superconductivity in pressurized RP nickelates, underscoring the central role of the bilayer structural motif.
Categories: cond-mat.str-el