Study of HTS Nanobridge Josephson Junctions made by FIB
Study of HTS Nanobridge Josephson Junctions made by FIB
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FIB高温超导纳米桥约瑟夫森结的研究
DOI：
10.1109/tasc.2022.3206226
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发表时间：
2022
影响因子：
1.8
通讯作者：
and S. Tanaka
中科院分区：
文献类型：
--
作者：
K. Hayashi;R. Ohtani;Y. Tottori;S. Ariyoshi;and S. Tanaka
在高温超导量子干涉器件(SQUID)中，人工双晶结经常被用于约瑟夫森结。然而，使用双晶衬底的结价格昂贵，而且其特性变化很大。此外，SQUID在衬底上的放置仅限于线性双晶结。另一方面，超导体-收缩-超导体(SCS)结是一种通过聚焦离子束(FIB)辐照来控制超导薄膜临界电流的技术。我们通过对YBa2Cu3O7-δ(YBCO)薄膜进行离子轰击制备了离子损伤结和纳米桥结，这是一种SCS结。通过对YBCO薄膜进行线扫描，在归一化注量下制备了离子损伤结，充分降低了临界电流。纳米桥结是通过使用FIB使YBCO薄膜的宽度变窄来制备的。制作了鱿鱼来演示这两种类型的约瑟夫森结的操作。纳米桥型表现出相对较大的调制幅度。
Artificial bicrystal junctions are often used for Josephson junctions in high-temperature superconductor superconducting quantum interference devices (SQUIDs). However, the junctions using bicrystal substrates are expensive and have large variations in their characteristics. Furthermore, the placement of SQUIDs on substrate is limited to only linear bicrystal junctions. On the other hand, the superconductor-constriction-superconductor (ScS) junction is a technique that is used to control the critical current of a superconductor thin film by focused ion beam (FIB) irradiation. We have fabricated ion damage junctions and nanobridge junctions, which are a kind of ScS junction, by FIB processing of YBa2Cu3O7-δ(YBCO) thin films. The ion damage junctions are fabricated by line scanning of YBCO thin films at normalization fluence, which sufficiently reduces the critical current. The nanobridge junctions are fabricated by narrowing the width of YBCO thin films using FIB. SQUIDs were fabricated to demonstrate the operation of both types of Josephson junctions. The nanobridge type showed relatively a larger modulation amplitude.