Calculation of penetration depth under various numerical models for the reflection-type two-coil mutual inductance technique. (1st March 2023)

• Record Type: Journal Article
• Authors: Liu, Ningning; Yao, Gang; Qu, Yueqiao; Wang, Xutao; Wang, Jinyue; Zhang, Wenxuan; Duan, Mingchao; Guan, Dan-Dan; Wang, Shiyong; Zheng, Hao; Li, Yao-Yi; Liu, Canhua; Jia, Jin-Feng
• Is Part Of: Superconductor science & technology. Volume 36:Number 3(2023)
• Publication Date: 2023-03-01
• Subjects: superconducting film -- two-coil mutual inductance measurement -- magnetic penetration depth -- superfluid density -- numerical model; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/acb08d
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: The two-coil mutual inductance (TCMI) technique is a useful experimental method to derive the magnetic penetration depth λ in a superconducting film after proper numerical calculations, in which various film geometries including infinite, circular and quadrangle films have been utilized. Based on previously reported reflection-type TCMI experimental data taken from NbN and K-adsorbed FeSe thin films, we investigate the validity of various numerical models with different geometries by comparing their calculation results. The calculated values of λ for various film geometries become identical only when the film size is at least three times larger than the coil size. For a rectangular film with a width comparable to the coil size, the numerical models of circular and square film geometries with proper sizes can also be adopted to obtain a similar λ value as that calculated with a rectangular film geometry. Although the true value of λ can be approximately achieved only after a complicated calibration, its calculated temperature dependence is insensitive to the choice of numerical models. With these results, a proper film geometry for the numerical calculation of λ may be selected to effectively improve the calculation efficiency.