Lattice compression has emerged as a fundamental tuning parameter for nickelate superconductivity. Pressure acts as a trigger to induce superconductivity in bulk Ruddlesden-Popper nickelates. For infinite-layer nickelate thin films, compressive epitaxial strain and rare-earth ion chemical pressure have been used to substantially enhance the superconducting transition temperature (Tc). Efforts to go further have been constrained by the limits of epitaxial stability or the challenges of measuring thin films in high-pressure environments. Here, we overcome this limitation by developing a technique to incorporate freestanding infinite-layer Nd0.85Sr0.15NiO2 membranes into a diamond anvil cell. Using this platform, we observe a strong increase in Tc up to our highest measurement pressure of ∼90 GPa, where a superconducting downturn can be observed near liquid nitrogen temperatures. Strikingly, we find a simple linear enhancement of Tc at a rate of 0.65 K GPa−1, with no signs of saturation. This suggests that the pairing strength in infinite-layer nickelates can be raised to a surprisingly high scale, using an approach that can be broadly applied to many two-dimensional materials.
@article{arxiv.2604.09525,
title = {High-temperature superconductivity in Nd$_{0.85}$Sr$_{0.15}$NiO$_2$ membranes under pressure},
author = {Yonghun Lee and Mengnan Wang and Xin Wei and Yijun Yu and Wendy L. Mao and Yu Lin and Harold Y. Hwang},
journal= {arXiv preprint arXiv:2604.09525},
year = {2026}
}