Nucleation of vortices inside open and blind microholes
Nucleation of vortices inside open and blind microholes
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DOI：
10.1103/physrevb.53.8553
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发表时间：
1996-04-01
影响因子：
3.7
通讯作者：
Pannetier, B
中科院分区：
文献类型：
--
作者：
Bezryadin, A;Ovchinnikov, YN;Pannetier, B
本文从理论上求出了具有盲孔的超导薄膜的临界场。结果表明，临界场的大小对海底厚度敏感，而轨道动量，在孔内成核的涡流的数量不敏感。本文导出了台阶状薄膜的一个简单边界条件，并用于微盘和孔附近超导形核的比较数值分析。通过增加盲孔底部的厚度，可以将孔转变成相同半径的圆盘，该圆盘位于膜的顶部。我们表明，这种转变导致的数量的旋涡成核的临界磁场内的孔（磁盘）的周长跳跃。我们还报道了具有开孔或盲孔晶格的超导薄膜的Bitter装饰实验结果。它被发现（根据计算），底部的厚度只有一个弱的影响，在一个恒定的垂直磁场中的样品冷却过程中的孔捕获的涡的数量。所有的实验结果都是在假设孔内成核的涡在冷却过程中停留在孔内，没有额外的涡进入孔内的情况下解释的。
The critical field of a thin superconducting film with a blind circular hole is found theoretically. It is shown that the value of the critical field is sensitive to the bottom thickness, but the orbital momentum, i.e., the number of vortices which nucleate inside the hole, is not sensitive. A simple boundary condition for a steplike thin film is derived acid used for comparative numerical analysis of the superconductivity nucleation in a microdisk and near the hole. By increasing the thickness of the bottom of a blind hole one can transform the hole into a disk of the same radius which rests on top of the film. We show that such transformation leads to a jump in the number of vortices which nucleate at the critical magnetic field inside the perimeter of the hole (the disk). We report also the results of the Bitter decoration experiments of a thin superconducting film with a lattice of open or blind holes. It is found (in accordance with the calculation) that the bottom thickness has only a weak influence on the number of vortices captured by a hole during the cooling of the sample at a constant perpendicular magnetic field. All the experimental results are explained under the assumption that the vortices nucleated inside a hole rest inside during the cooling process and no additional vortices enter the hole.