Ultrathin Limit on the Anisotropic Superconductivity of Single-Layered Cuprate Films

• Published in: Chinese physics letters Vol. 41; no. 2; pp. 27401 - 101
• Main Authors: Ran, Feng, Chen, Pan, Li, Dingyi, Xiong, Peiyu, Fan, Zixin, Ling, Haoming, Liang, Yan, Zhang, Jiandi
• Format: Journal Article
• Language: English
• Published: Chinese Physical Society and IOP Publishing Ltd 01.02.2024
• ISSN: 0256-307X; 1741-3540
• DOI: 10.1088/0256-307X/41/2/027401

Exploring dimensionality effects on cuprates is important for understanding the nature of high-temperature superconductivity. By atomically layer-by-layer growth with oxide molecular beam epitaxy, we demonstrate that La 2– x Sr x CuO 4 ( x = 0.15) thin films remain superconducting down to 2 unit cells of thickness but quickly reach the maximum superconducting transition temperature at and above 4 unit cells. By fitting the critical magnetic field ( μ 0 H c2 ), we show that the anisotropy of the film’s superconductivity increases with decreasing film thickness, indicating that the superconductivity of the film gradually evolves from weak three- to two-dimensional character. These results are helpful to gain more insight into the nature of high-temperature superconductivity with dimensionality.