Phase transitions in thin mesoscopic superconducting disks
Phase transitions in thin mesoscopic superconducting disks
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DOI：
10.1103/physrevb.57.13817
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发表时间：
1998-06
影响因子：
3.7
通讯作者：
V. Schweigert;F. Peeters
中科院分区：
文献类型：
--
作者：
V. Schweigert;F. Peeters
通过自洽求解两个Ginzburg-Landau（GL）方程，研究了不同超导态之间以及介观圆盘超导正常态之间的相变。对于比相干长度薄的圆盘，我们将自己限制在具有固定角动量的超导状态。我们发现相变的类型取决于圆盘的尺寸，即半径和厚度。通过对线性化第一 GL 方程的本征函数进行展开，我们开发了一种分析方法，使我们能够预测相变类型并找到相变点附近的系统特性。分析结果与我们使用有限差分技术求解耦合到三维麦克斯韦方程的非线性 GL 方程所获得的模拟结果非常一致。预测了具有相同角动量的不同超导态之间的新型一阶相变。
Phase transitions between different superconducting states and between the superconducting-normal state of mesoscopic disks are studied by solving the two Ginzburg-Landau (GL) equations self-consistently. We limit ourselves to superconducting states with a fixed angular momentum for disks thinner than the coherence length. We find that the type of phase transition depends on the disk size, namely, both the radius and the thickness. Using an expansion over the eigenfunction of the linearized first GL equation, we develop an analytical approach that allows us to predict the type of phase transition and find the system characteristics near the phase transition point. The analytical results are in good agreement with results from our simulation obtained by using finite-difference techniques to solve the nonlinear GL equations coupled to the three-dimensional Maxwell equations. A new type of first-order phase transition between different superconducting states having the same angular momentum is predicted.