Superconductivity in a quintuple-layer square-planar nickelate
Max Planck Quantum Matter Seminar
- Date: Sep 30, 2021
- Time: 03:00 PM - 04:00 PM (Local Time Germany)
- Speaker: Julia Mundy
- Harvard University
- Location: online via Zoom
- Host: Gregor Jotzu
Since the discovery of high-temperature superconductivity in the copper oxide materials, there have been sustained efforts to both understand the origins of this phase and discover new cuprate-like superconducting materials. One prime materials platform has been the rare-earth nickelates and indeed superconductivity was recently discovered in the doped compound Nd0.8Sr0.2NiO2. Undoped NdNiO2 belongs to a series of layered square-planar nickelates with chemical formula Ndn+1NinO2n+2 and is known as the 'infinite-layer' (n=∞) nickelate. Here, we report the synthesis of the quintuple-layer (n=5) member of this series, Nd6Ni5O12, in which optimal cuprate-like electron filling (d8.8) is achieved without chemical doping. We observe a superconducting transition beginning at ∼13 K. Electronic structure calculations, in tandem with magnetoresistive and spectroscopic measurements, suggest that Nd6Ni5O12 interpolates between cuprate-like and infinite-layer nickelate-like behavior. In engineering a distinct superconducting nickelate, we identify the square-planar nickelates as a new family of superconductors which can be tuned via both doping and dimensionality.