Center for Nonlinear Studies and Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
J Phys Condens Matter. 2013 Aug 28;25(34):345703. doi: 10.1088/0953-8984/25/34/345703.
Exotic vortex states with long range attraction and short range repulsion have recently been proposed to arise in certain superconducting hybrid structures such as type-I/type-II layered systems as well as multi-band superconductors. In previous work it has been shown that such systems can form clump or phase separated states, but little is known about how they behave in the presence of pinning and under an applied drive. Using large scale simulations we examine the static and dynamic properties of such vortex states interacting with random and periodic pinning. In the absence of pinning this system does not form patterns but instead undergoes complete phase separation. When pinning is present there is a transition from inhomogeneous to homogeneous vortex configurations similar to a wetting phenomenon. Under an applied drive, a dynamical dewetting process can occur from a strongly pinned homogeneous state into pattern forming states, such as moving stripes that are aligned with the direction of drive or moving labyrinth or clump phases. We show that a signature of the exotic vortex interactions observable with transport measurements is a robust double peak feature in the differential resistance curves. Our results should be valuable for determining whether such vortex interactions are occurring in these systems and also for addressing the general problem of systems with competing interactions in the presence of random and periodic pinning.
最近有人提出，在某些超导混合结构中，如 I 型/II 型层状系统以及多带超导体中，会出现具有长程吸引和短程排斥的奇异涡旋态。在之前的工作中已经表明，这样的系统可以形成团簇或相分离状态，但对于它们在钉扎存在和外加驱动下的行为，人们知之甚少。我们使用大规模模拟来研究与随机和周期性钉扎相互作用的这种涡旋态的静态和动态特性。在没有钉扎的情况下，这个系统不会形成图案，而是经历完全的相分离。当存在钉扎时，从非均匀到均匀的涡旋构型的转变类似于润湿现象。在外加驱动下，从强烈钉扎的均匀状态到图案形成状态（例如与驱动方向对齐的移动条纹或移动迷宫或团簇相）可能会发生动态去湿过程。我们表明，通过输运测量观察到的奇异涡旋相互作用的特征是差分电阻曲线中稳健的双峰特征。我们的结果对于确定这些系统中是否存在这种涡旋相互作用以及解决具有竞争相互作用的系统在随机和周期性钉扎存在下的一般问题都应该是有价值的。
