圆对称环域Josephson结中准磁通量子激发对外磁场的依赖关系  

THE MAGNETIC FIELD DEPENDENCE OF THE QUASI-FLU- XON OF EXCITATION IN THE CIRCULAR SYMMETRIC ANNULAR JOSEPHSON JUNCTION

作　　者：徐昆明[1] 沈亚菲 姚希贤[3] 

机构地区：[1]浙江大学物理系 [2]东南大学计算科学与工程系 [3]南京大学物理系

出　　处：《物理学报》1989年第6期938-946,共9页Acta Physica Sinica

摘　　要：本文研究了在外磁场中圆对称环域Josephson结的环形准磁通量子运动.准磁通量子的激发对外磁场的依赖关系与结的几何尺寸有关.对结宽度 αγο-γο= 5λ的环域结,外磁场使准磁通量子的寿命增加;对 αγο-γο= 10λ的环域结,外磁场除了产生上述效应外,还影响准磁通量子运动的细节.外磁场还使第一零场台阶向低驱动电流方向扩展.无疑地,这些变化是与外磁场在结中的不均匀分布密切相关.本文同时讨论了可调Josephson振荡器的一个合理方案.In the case of existence of an applied magnetic field, the movement of the ring-shape quasi-fluxons in the circular symmetric annular Josephson junctions is investigated numerically. The behavoir of the quasi-fluxons in an applied field depends upon the geometric size of the junctions. If the width of the annular junctions is 5λJ in the radial direction, the life time of the quasi-fluxon is increased by applied field. If the width of the annular junction is 10λJ, the life dme of the quasi-fluxon is increased as well, and in addition, some evident changes of the behavior of the quasi-fluxons occur in the process of propagation and in the reflection at the boundary, due to the applied field. The size of the first zero-field step increases with applied field in the lower current direction. These changes are caused by an inhomo-geous distribution of the applied field in the junctions. A tunable resonator in the gigahertz-range using quasi-fluxons on a lossy large-area annular Josephson junction is also proposed in this paper.

关 键 词：无线电物理学 量子激发 外磁场 

分 类 号：O455[理学—无线电物理]