Detection of the superconducting transition and magnetic flux trapping in a niobium micro-ring by using micro-Hall sensors

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• 作者：Yung Ho Kahng ; Yun Won Kim ; Mun Seog Kim…
• 关键词：Superconductivity ; Magnetic flux ; Nb micro ; ring ; Micro ; Hall sensor
• 刊名：Journal of the Korean Physical Society
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：69
• 期：9
• 页码：1456-1461
• 全文大小：756 KB
• 刊物主题：Physics, general; Theoretical, Mathematical and Computational Physics; Particle and Nuclear Physics;
• 出版者：Springer Netherlands
• ISSN：1976-8524
• 卷排序：69

文摘

An InAs heterostructure-based micro-Hall sensor was used to study the magnetic properties of a superconducting Nb micro-ring, enabling observation of magnetic phenomena such as diamagnetism onset and magnetic flux trapping in the 20-μm-diameter sample. The superconducting diamagnetism of the micro-ring was observed to develop slowly from T = 7.5 K down to 5 K and showed a notably sharp and substantial drop at 7.0 K, the zero-resistivity temperature obtained from transport measurements on a strip-patterned sample. The observed superconducting transition is discussed in terms of a percolation scenario. In magnetic-field-cooling measurements, the Hall signal from the magnetic flux trapped in the Nb ring at 4.5 K was detected at a sufficiently high level for quantitative comparison with the estimate.