当前位置: X-MOL 学术Supercond. Sci. Technol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Field Cooled Annular Josephson Tunnel Junctions
Superconductor Science and Technology ( IF 3.6 ) Pub Date : 2020-06-16 , DOI: 10.1088/1361-6668/ab92e7
Roberto Monaco 1, 2 , Jesper Mygind 3 , Valery P Koshelets 4
Affiliation  

We investigate the physics of planar annular Josephson tunnel junctions quenched through their transition temperature in the presence of an external magnetic field. Experiments carried out with long Nb/Al-AlOx/Nb annular junctions showed that the magnetic flux trapped in the high-quality doubly-connected superconducting electrodes forming the junction generates a persistent current whose associated magnetic field affects the both the static and dynamics properties of the junctions. More specifically, the field trapped in the hole of one electrode combined with a d.c. bias current induces a viscous flow of dense trains of Josephson vortices which manifests itself through the sequential appearance of displaced linear slopes, Fiske step staircases and Eck steps in the junction's current-voltage characteristic. Furthermore, a field shift is observed in the first lobe of the magnetic diffraction pattern. The effects of the persistent current can be mitigated or even canceled by an external magnetic field perpendicular to the junction plane. The radial field associated with the persistent current can be accurately modeled with the classical phenomenological sine-Gordon model for extended one-dimensional Josephson junctions. Extensive numerical simulations were carried out to disclose the basic flux-flow mechanism responsible for the appearance of the magnetically induced steps and to elucidate the role of geometrical parameters. It was found that the imprint of the field cooling is enhanced in confocal annular junctions which are the natural generalization of the well studied circular annular junctions.

中文翻译:

场冷环形约瑟夫森隧道接头

我们研究了在存在外部磁场的情况下通过转变温度淬火的平面环形约瑟夫森隧道结的物理特性。用长 Nb/Al-AlOx/Nb 环形结进行的实验表明,形成结的高质量双连接超导电极中捕获的磁通量会产生持续电流,其相关磁场会影响静态和动态特性。路口。更具体地说,被困在一个电极的孔中的场与直流偏置电流相结合会引起密集的约瑟夫森涡流的粘性流动,这通过在结电流中连续出现的位移线性斜率、Fiske 阶梯和 Eck 阶梯而表现出来-电压特性。此外,在磁衍射图的第一瓣中观察到场位移。通过垂直于结平面的外部磁场可以减轻甚至消除持续电流的影响。与持续电流相关的径向场可以用经典的现象学正弦-戈登模型精确建模,用于扩展的一维约瑟夫森结。进行了广泛的数值模拟,以揭示导致磁感应台阶出现的基本通量流动机制,并阐明几何参数的作用。发现场冷却的印记在共焦环形结中得到增强,这是已充分研究的圆形环形结的自然概括。通过垂直于结平面的外部磁场可以减轻甚至消除持续电流的影响。与持续电流相关的径向场可以用经典的现象学正弦-戈登模型精确建模,用于扩展的一维约瑟夫森结。进行了广泛的数值模拟,以揭示导致磁感应台阶出现的基本通量流动机制,并阐明几何参数的作用。发现场冷却的印记在共焦环形结中得到增强,这是已充分研究的圆形环形结的自然概括。通过垂直于结平面的外部磁场可以减轻甚至消除持续电流的影响。与持续电流相关的径向场可以用经典的现象学正弦-戈登模型精确建模,用于扩展的一维约瑟夫森结。进行了广泛的数值模拟,以揭示导致磁感应台阶出现的基本通量流动机制,并阐明几何参数的作用。发现场冷却的印记在共焦环形结中得到增强,这是已充分研究的圆形环形结的自然概括。与持续电流相关的径向场可以用经典的现象学正弦-戈登模型精确建模,用于扩展的一维约瑟夫森结。进行了广泛的数值模拟,以揭示导致磁感应台阶出现的基本通量流动机制,并阐明几何参数的作用。发现场冷却的印记在共焦环形结中得到增强,这是已充分研究的圆形环形结的自然概括。与持续电流相关的径向场可以用经典的现象学正弦-戈登模型精确建模,用于扩展的一维约瑟夫森结。进行了广泛的数值模拟,以揭示导致磁感应台阶出现的基本通量流动机制,并阐明几何参数的作用。发现场冷却的印记在共焦环形结中得到增强,这是已充分研究的圆形环形结的自然概括。进行了广泛的数值模拟,以揭示导致磁感应台阶出现的基本通量流动机制,并阐明几何参数的作用。发现场冷却的印记在共焦环形结中得到增强,这是已充分研究的圆形环形结的自然概括。进行了广泛的数值模拟,以揭示导致磁感应台阶出现的基本通量流动机制,并阐明几何参数的作用。发现场冷却的印记在共焦环形结中得到增强,这是已充分研究的圆形环形结的自然概括。
更新日期:2020-06-16
down
wechat
bug