We report measurements of the Nernst and Seebeck effects in Nd1−xSrxNiO2 thin films near the superconducting transition temperature, T = 6.5 - 15 K. Our main result is the observation of a vortex-Nernst signal Syx(T,H) with a maximum at μ0H = 5 T and a tail that extends to μ0H≈ 15 T, which we identify as the upper-critical field Hc2. At T>Tc= 6.1 K, Hc2 remains large (15 T), up to the highest temperature we can resolve from Syx (11 K). These results indicate the existence of a vortex-liquid state over a wide range of finite-resistance temperatures, as in the high-Tc cuprates.
@article{arxiv.2309.03170,
title = {The vortex-Nernst effect in a superconducting infinite-layer nickelate},
author = {Nicholas P. Quirk and Danfeng Li and Bai Yang Wang and Harold Y. Hwang and N. P. Ong},
journal= {arXiv preprint arXiv:2309.03170},
year = {2023}
}