Nica, Emilian M.Krishna, JyotiYu, RongSi, QimiaoBotana, Antia S.Erten, Onur2020-10-092020-10-092020Nica, Emilian M., Krishna, Jyoti, Yu, Rong, et al.. "Theoretical investigation of superconductivity in trilayer square-planar nickelates." <i>Physical Review B,</i> 102, no. 2 (2020) American Physical Society: https://doi.org/10.1103/PhysRevB.102.020504.https://hdl.handle.net/1911/109403The discovery of superconductivity in Sr-doped NdNiO2 is a crucial breakthrough in the long pursuit for nickel oxide materials with electronic and magnetic properties similar to those of the cuprates. NdNiO2 is the infinite-layer member of a family of square-planar nickelates with general chemical formula Rn+1NinO2n+2 (R = La, Pr, Nd, n=2,3,...∞). In this Rapid Communication, we investigate superconductivity in the trilayer member of this series (R4Ni3O8) using a combination of first-principles and t−J model calculations. R4Ni3O8 compounds resemble cuprates more than RNiO2 materials in that only Ni-dx2−y2 bands cross the Fermi level, they exhibit a largely reduced charge transfer energy, and as a consequence superexchange interactions are significantly enhanced. We find that the superconducting instability in doped R4Ni3O8 compounds is considerably stronger with a maximum gap about four times larger than that in Sr0.2Nd0.8NiO2.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttps://doi.org/10.1103/PhysRevB.102.020504