计量学报2025，Vol.46Issue(5)：638-643,6.DOI:10.3969/j.issn.1000-1158.2025.05.03
高温超导双晶约瑟夫森结的本征临界电流测量
Measurement of Intrinsic Critical Currents of High-Temperature Superconducting Bicrystal Josephson Junctions
摘要
Abstract
The benefits of the high-temperature superconducting Josephson junction works in the liquid nitrogen temperature region,and has low cooling cost,so it can be applied to superconducting quantum interference devices,quantum voltage standard devices,etc.We fabricated yttrium-barium-copper-oxygen(YBCO)/gold(Au)bilayer film on SrTiO3 bicrystal substrate,and prepared YBCO bicrystal Josephson junction by ultraviolet lithography and ion beam etching.The resistance-temperature(R-T)characteristic curves and voltage-current(V-I)characteristic curves of the YBCO bicrystal Josephson junction were measured in the liquid nitrogen temperature region.From the R-T curve,it was observed that the prepared YBCO bicrystal Josephson junction had obvious resistance tailing.The intrinsic critical current value of the high-temperature superconducting Josephson junction was obtained by using the geometric averaging method from selecting the appropriate data range and applying a hyperbolic function fitting method to eliminate the influence of noise rounding effect and self-heating effect on the critical current.After fitting the intrinsic critical current from the selected V-I data,noticeable noise rounding effects were observed in each YBCO bicrystal structure.Only the 2 μm-wide YBCO bicrystal structure showed significant susceptibility to self-heating effects,whereas the 4 μm,6 μm,8 μm,and 10 μm-wide YBCO bicrystal structures exhibited minor influence from self-heating effects.关键词
电学计量/高温超导/本征临界电流/双晶约瑟夫森结/钇钡铜氧Key words
electrical metrology/high-temperature-superconducting/intrinsic critical current/bicrystal Josephson junction/YBCO引用本文复制引用
孙永,徐达,陈晴,王雪深,李劲劲,赵建亭,钟青..高温超导双晶约瑟夫森结的本征临界电流测量[J].计量学报,2025,46(5):638-643,6.基金项目
中国计量科学研究院基本科研业务费重点领域项目(AKYZD2211) （AKYZD2211）
