Finding unconventional superconductors in proximity to various strongly correlated electronic phases has been a recurring theme in materials as diverse as heavy fermion compounds, cuprates, pnictides, and twisted bilayer graphene. The recent discovery of superconductivity in layered nickelates1 was motivated by looking for an analog of the cuprates. The synthesis of the nickelates is in and of itself interesting – it involves the removal of planes of oxygen from a 3D nickel oxide using soft chemistry techniques. We will introduce this new family of superconductors and our current understanding of their electronic and magnetic structure. Notable aspects are a doping-dependent superconducting dome2, strong magnetic fluctuations3, instabilities towards charge stripes4, and a landscape of unusual normal state properties from which superconductivity emerges5. These features are strongly reminiscent of the cuprates, despite key differences in the electronic structure and the absence of a proximate correlated insulator.
1D. F. Li et al., Nature 572, 624 (2019).
2D. F. Li et al., Phys. Rev. Lett. 125, 027001 (2020).
3H. Lu et al., Science 373, 213 (2021).
4M. Rossi et al., Nat. Phys. 18, 869 (2022).
5K. Lee et al., arXiv: 2203.02580.