Priour D J, Fertig H A
Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, MD 20742-4111, USA.
Phys Rev Lett. 2004 Jul 30;93(5):057003. doi: 10.1103/PhysRevLett.93.057003.
Using Ginzburg-Landau theory, we find novel configurations of vortices in superconducting thin films subject to the magnetic field of a magnetic dot array, with dipole moments oriented perpendicular to the film. Sufficiently strong magnets cause the formation of vortex-antivortex pairs. In most cases, the vortices are confined to dot regions, while the antivortices can form a rich variety of lattice states. We propose an experiment in which the perpendicular component of the dot dipole moments can be tuned using an in-plane magnetic field. We show that in such an experiment the vortex-antivortex pair density shows broad plateaus as a function of the dipole strength. Many of the plateaus correspond to vortex configurations that break dot lattice symmetries. In some of these states, the vortex cores are strongly distorted. Possible experimental consequences are mentioned.
利用金兹堡 - 朗道理论，我们发现了超导薄膜中涡旋的新型构型，该薄膜受到磁点阵列的磁场作用，磁偶极矩垂直于薄膜取向。足够强的磁体会导致涡旋 - 反涡旋对的形成。在大多数情况下，涡旋局限于点区域，而反涡旋可以形成丰富多样的晶格态。我们提出了一个实验，其中可以使用平面内磁场来调节点偶极矩的垂直分量。我们表明，在这样的实验中，涡旋 - 反涡旋对密度作为偶极强度的函数呈现出宽广的平台区。许多平台区对应于破坏点晶格对称性的涡旋构型。在其中一些状态下，涡旋核心会严重扭曲。文中提到了可能的实验结果。
