Superconductivity in freestanding infinite-layer nickelate membranes

TL;DR

This paper reports the synthesis of freestanding superconducting nickelate membranes, enabling new manipulation and investigation methods for high-temperature superconductivity beyond epitaxial films.

Contribution

It introduces a novel approach to create freestanding nickelate membranes, facilitating advanced studies and potential enhancements of superconducting properties.

Findings

Superconducting La0.8Sr0.2NiO2 membranes with Tc of 10.9 K were synthesized.

Interface engineering and quick transfer are crucial for achieving superconductivity.

The platform enables investigations into pairing symmetry and higher Tc via high-pressure experiments.

Abstract

The observation of superconductivity in infinite-layer nickelates has attracted significant attention due to its potential as a new platform for exploring high $ \mathrm{\textit{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 $ \mathrm{La}_{0.8}\mathrm{Sr}_{0.2}\mathrm{Ni}\mathrm{O}_{2} $ membranes ($ \mathrm{\textit{T}}_{c}\mathrm{=}\mathrm{10.9}\;\mathrm{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 $ \mathrm{\textit{T}}_{c} $ values via high-pressure experiments.