新型非常规高温超导材料——镍酸盐薄膜研究进展OA

This article systematically reviews recent progress in nickelate superconducting thin films.As the third class of high temperature superconductors after cuprates and iron-based superconductors,nickelates provide a new platform for exploring the mechanism of high temperature superconductivity.This review focuses on two major thin-film systems:the infinite-layer phase and the Ruddlesden-Popper(RP)phase.We first summarize the synthesis of infinite-layer nickelates by topotactic reduction,together with their doping phase diagrams and correlated electronic phenomena.And then we describe the breakthrough in achieving superconductiv-ity at ambient pressure in RP phase bilayer nickelates through epitaxial growth.Based on advanced spectroscopic studies,we further analyze their multiorbital electronic structure,superconducting gap features,and possible spin and charge order.Through comparison of these two systems,this review shows that the infinite-layer phase is closer to quasi-two-dimensional single-band physics,whereas the RP phase involves strong interlayer coupling and multiorbital physics.Under the shared framework of NiO2 planes and strong corre-lations,the two systems display distinct microscopic pictures,providing a key comparison for checking theories of unconventional superconductivity.