Superconductivity in freestanding infinite-layer nickelate membranes

The observation of superconductivity in infinite-layer nickelates has attracted significant attention due to its potential as a new platform for exploring high T_c superconductivity. However, thus far, superconductivity has only been observed in epitaxial thin films, which limits the manipulation capabilities and modulation methods compared to two-dimensional exfoliated materials. Given the exceptionally giant strain tunability and stacking capability of freestanding membranes, separating superconducting nickelates from the as-grown substrate is a novel way to engineer the superconductivity and uncover the underlying physics. Herein, we report the synthesis of the superconducting freestanding La_0.8Sr_0.2NiO_2 membranes (T_c=10.9 K), emphasizing the crucial roles of the interface engineering in the precursor phase film growth and the quick transfer process in achieving superconductivity. Our work offers a new versatile platform for investigating the superconductivity in nickelates, such as the pairing symmetry via constructing Josephson tunneling junctions and higher T_c values via high-pressure experiments.