Electron-doping Ruddlesden-Popper nickelate

Abstract

The discovery of cuprate and iron-based superconductors in the last three decades has stimulated a great enthusiasm in researching high T C superconductors. For cuprate, a lot of superconducting compounds were discovered and the superconducting behavior can be tuned by changing the number of the layer. Currently, a cuprate-like superconductor, i.e., nickelate, is reported, which opens a new era in the field of superconductivity. However, the superconducting behavior is only limited in quite a few nickelate compounds. Here, based on first-principles calculations, we investigate the electronic band structure of Ruddlesden Popper (RP) phase and reduced RP (rRP) phase nickelates, and the electron doping influences on these phases. Our results further indicate that the most effective electron-doping selection for these RP/rRP phases is the fluorine replacing the oxygen sites (FO) of LaO or layer to control the electron state. This doping not only introduces electrons to system but also keeps the effective single band. Our theoretical predictions would contribute to the discovering of more possible nickelate superconductors.