Córdoba-Camacho W Y, da Silva R M, Barba-Ortega J, Albino Aguiar J
Departamento de Física, Universidade Federal de Pernambuco, Avenida Jornalista Aníbal Fernandes, s/n, Cidade Universitária, 50740-560, Recife, PE, Brazil.
Departamento de Física, Universidad Nacional de Colombia, Bogotá, Colombia.
J Phys Condens Matter. 2020 Mar 10;33(10):105902. doi: 10.1088/1361-648X/abd118.
We demonstrate that the presence of edges in a superconducting film made of a type-I/type-II bilayer stabilizes type-II/type-I hybrid (inter-type) flux patterns, as vortex clusters, chains, and gel phase. These patterns are very sensitive to primary parameters such as applied magnetic field, layer coupling, and temperature. Thus, the magnetization versus temperature curves, M(T), for many values of coupling were used to estimate the strength of the layer couplings, and also as a guide for obtaining sequentially the flux patterns. We also show that the effect of the borders on the unrestricted states is to shift them to states of higher density, since they introduce extra compression on the vortex matter. For a low layer coupling regime, we observe an unusual magnetic response where few partial vortices (partial in a sense they miss the contribution of the type I part), repelling each other and bounded to the surfaces, populate one layer leaving the other empty. We expect that the predicted flux configurations can stimulate experimentalists in trying to observe them by direct imaging techniques.
我们证明，由I型/II型双层制成的超导薄膜中边缘的存在会稳定II型/I型混合（跨类型）磁通模式，如涡旋簇、链和凝胶相。这些模式对诸如施加磁场、层间耦合和温度等主要参数非常敏感。因此，利用许多耦合值下的磁化强度与温度曲线M(T)来估计层间耦合强度，并作为依次获得磁通模式的指导。我们还表明，边界对无限制状态的影响是将它们转移到更高密度的状态，因为它们会对涡旋物质引入额外的压缩。对于低耦合层状态，我们观察到一种不寻常的磁响应，即很少有部分涡旋（从某种意义上说，部分涡旋缺少I型部分的贡献），它们相互排斥并束缚在表面，填充一层而使另一层为空。我们期望所预测的磁通配置能够激发实验人员尝试通过直接成像技术来观察它们。
