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arXiv · 2309.03170

The vortex-Nernst effect in a superconducting infinite-layer nickelate

Nicholas P. Quirk·Danfeng Li·Bai Yang Wang·Harold Y. Hwang·N. P. Ong
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Abstract

We report measurements of the Nernst and Seebeck effects in Nd$_{1-x}$Sr$_x$NiO$_2$ thin films near the superconducting transition temperature, $T$ = 6.5 - 15 K. Our main result is the observation of a vortex-Nernst signal $S_{yx}(T,H)$ with a maximum at $\mu_0H$ = 5 T and a tail that extends to $\mu_0H$ $\approx$ 15 T, which we identify as the upper-critical field $H_{c2}$. At $T > T_{\rm c} =$ 6.1 K, $H_{c2}$ remains large (15 T), up to the highest temperature we can resolve from $S_{yx}$ (11 K). These results indicate the existence of a vortex-liquid state over a wide range of finite-resistance temperatures, as in the high-$T_{\rm c}$ cuprates.

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Nicholas P. Quirk, Danfeng Li, Bai Yang Wang, Harold Y. Hwang, N. P. Ong. 2023-09-06. The vortex-Nernst effect in a superconducting infinite-layer nickelate. https://arxiv.org/abs/2309.03170

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