2025/12/24 by Qingming Huang, Huang, Qingming, Xiaofang Fu +9
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.2512.20928
openalex publication_date 2025/12/24 · openalex created_date 2025/12/26 · openalex updated_date 2026/07/28
The discovery of superconducting nickelates provides a unique opportunity to explore the pairing mechanism of high-temperature superconductivity. Here, we use ultrafast terahertz spectroscopy to probe the temperature-dependent superfluid density in an infinite-layer samarium nickelate film with a Tc of 20 K. The superfluid density decreases linearly with rising temperature, consistent with clean limit d-wave pairing. From this linear relation, we extract a superconducting gap of 2.5 meV and a gap-to-Tc ratio of 3, suggesting that this sample lies in the weak-coupling limit. Furthermore, the ratio of the mean free path to the coherence length, is determined to be 1.5, confirming the clean-limit behavior. These findings establish strong parallels between the pairing mechanisms in nickelate and cuprate superconductors.