Evolution of the Superfluid Density in Infinite-Layer Nickelates

Bai Yang Wang; Shannon P. Harvey; Kyuho Lee; Yijun Yu; Yonghun Lee; Motoki Osada; Chaitanya Murthy; Srinivas Raghu; Harold Y. Hwang

arXiv · 2603.05606

Evolution of the Superfluid Density in Infinite-Layer Nickelates

Bai Yang Wang·Shannon P. Harvey·Kyuho Lee·Yijun Yu·Yonghun Lee·Motoki Osada·Chaitanya Murthy·Srinivas Raghu·Harold Y. Hwang

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Abstract

Nickelate superconductors provide a valuable new platform for the study of unconventional superconductivity that is complementary to the cuprates. One of the central puzzles about high-temperature superconductors is what factors determine the scale of their superconducting transition temperature ($T_\mathrm{c}$). To address this question for infinite-layer nickelates, we present a systematic mutual inductance study of the superfluid density across the doping-dependent superconducting dome of $\mathrm{Nd}_{1-x}\mathrm{Sr}_x\mathrm{NiO}_2$. We observe a weak superfluid stiffness that exhibits an approximately square-root correlation with $T_\mathrm{c}$. We also find a strong interplay between Nd magnetism and the superconducting phase, manifested as a substantial low-temperature suppression of superfluid density. These observations highlight the importance of superconducting phase fluctuations in limiting $T_\mathrm{c}$ and unexpectedly strong coupling between the Nd 4$f$ moments and the superfluid.

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Bai Yang Wang, Shannon P. Harvey, Kyuho Lee, Yijun Yu, Yonghun Lee, Motoki Osada, Chaitanya Murthy, Srinivas Raghu, Harold Y. Hwang. 2026-03-05. Evolution of the Superfluid Density in Infinite-Layer Nickelates. https://arxiv.org/abs/2603.05606

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