小的内半径圆对称环域Josephson结中孤子行为的研究  

THE BEHAVIOR OF SOLITON STATES IN CIRCULARLY SYMMETRIC ANNULAR JOSEPHSON JUNCTION WITH SMALL INNER RADIUS

作　　者：徐昆明[1] 陆道芳[1] 姚希贤[2] 

机构地区：[1]浙江大学物理系,杭州310027 [2]南京大学物理系,南京210008

出　　处：《低温物理学报》1992年第4期293-304,共12页Low Temperature Physical Letters

基　　金：国家自然科学基金

摘　　要：环域结的位相差φ随时间演化的扰动Sine-Gordon方程(SGE)比in-line结的多出了与径向坐标ρ成反比的一项1/ρ (dφ)/(dρ),它的影响将随着ρ的减小而增大。我们的数值研究结果表明,不同的孤子行为出现在双孤子激发的状态:在内半径为7.5λ_J的环域结中,属于对称模式的双孤子激发只出现在低电流范围内,且在Ⅰ-Ⅴ曲线上呈现出迴滞现象;在内半径为50λ_J的环域结中,除了对称模式的激发外,还在高电流范围内出现串形模式的双孤子激发,在Ⅰ-Ⅴ曲线中也没有出现迴滞现象。In the perturbed sine-Gordon equation describing the time evolution of the phase-difference φ involved in the annular junctions, there is an excess termwhich is inversely proportional to p, in comparison with in-line junctions. The influence of this term upon the behaviour of the soliton excitations becomes significant as p becomes small. Our numerical investigation on the annular junctions shows, that there exist different aspects in the double-soliton state: Only the symmetric mode of double-soliton state appears in the annular junction with the size of 5λJ and ρ0 = 7.5λJ, and there is hysteresis in the I-V curves. For the annular junction with the same size but ρ0 = 50λJ, the symmetric mode of double-soliton state appears also for the low driven current range. Besides another mode, which is named as the bunched mode, of double-soliton state gives rise for the high driven current range, and there is no hysteresis in the I-V curve.

关 键 词：环域结 约瑟夫森结 孤子行为 

分 类 号：O511.2[理学—低温物理]