Sebastien Abadi, Stanford University

Abstract

 Superconductivity near 80 K was recently discovered in La2Ni3O7 under high pressure,  making it the first bulk nickelate to exhibit high temperature superconductivity. As a potential  analog to the unconventional superconductivity observed in the cuprates, the mechanism  behind the superconductivity in La2Ni3O7 is of great interest. A precise understanding of this  mechanism in turn requires a precise understanding of the electronic structure of La2Ni3O7. In  the present study, we performed ARPES experiments on La2Ni3O7 and measured its electronic  structure. Notably, we observe a flat band which lies close to the Fermi level, which may  contribute a high density of states that contributes to superconductivity. The details of this flat  band are liable to play a key role in the superconducting phase of La2Ni3O7, so our results are i mportant for understanding superconductivity in the nickelates, and by extension the cuprates  as well.