Paturi P, Malmivirta M, Hynninen T, Huhtinen H
Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, Finland.
J Phys Condens Matter. 2018 Aug 8;30(31):315902. doi: 10.1088/1361-648X/aad02b. Epub 2018 Jun 29.
A molecular dynamics (MD) simulation to simulate the vortices in superconductors with artificial pinning sites is presented. The simulation reproduces the correct anisotropic behavior in angular dependence of critical current. We also show that the shape of the [Formula: see text] curve depends on the size of the pinning sites and the change from p = 0.5 to [Formula: see text] is due to the breaking of the vortex lattice to individually acting vortices. The results beautifully correspond to experimental data. Furthermore, we found that the size and shape of the c-axis peak observed with columnar pinning sites in [Formula: see text] also depends on the size of the rods, larger pinning sites leading to wider peaks. The results obtained from the MD-simulation are similar to those of the much more computationally intensive Ginzburg-Landau simulations. Furthermore, the MD-simulations can provide insight to the vortex dynamics within the samples.
本文提出了一种分子动力学（MD）模拟方法，用于模拟具有人工钉扎位点的超导体中的涡旋。该模拟再现了临界电流角依赖性中正确的各向异性行为。我们还表明，[公式：见正文]曲线的形状取决于钉扎位点的大小，从p = 0.5到[公式：见正文]的变化是由于涡旋晶格破裂为单独作用的涡旋。这些结果与实验数据完美吻合。此外，我们发现，在[公式：见正文]中用柱状钉扎位点观察到的c轴峰的大小和形状也取决于棒的大小，较大的钉扎位点导致更宽的峰。MD模拟得到的结果与计算量更大的金兹堡-朗道模拟结果相似。此外，MD模拟可以深入了解样品内部的涡旋动力学。
