Geurts R, Milosević M V, Peeters F M
Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium.
Phys Rev Lett. 2006 Sep 29;97(13):137002. doi: 10.1103/PhysRevLett.97.137002. Epub 2006 Sep 28.
In submicron superconducting squares in a homogeneous magnetic field, Ginzburg-Landau theory may admit solutions of the vortex-antivortex type, conforming to the symmetry of the sample [L. F. Chibotaru, Nature (London) 408, 833 (2000)10.1038/35048521]. Here we show that these fascinating, but never experimentally observed states, can be enforced by artificial fourfold pinning, with their diagnostic features enhanced by orders of magnitude. The second-order nucleation of vortex-antivortex molecules can be driven by either temperature or an applied magnetic field, with stable asymmetric vortex-antivortex equilibria found on its path.
在均匀磁场中的亚微米超导正方形中，金兹堡 - 朗道理论可能允许涡旋 - 反涡旋类型的解，这与样品的对称性相符[L. F. 奇博塔罗，《自然》（伦敦）408, 833 (2000)10.1038/35048521]。在此我们表明，这些迷人但从未在实验中观测到的状态，可以通过人工四重钉扎来实现，其诊断特征会增强几个数量级。涡旋 - 反涡旋分子的二级成核可以由温度或外加磁场驱动，并且在其路径上会发现稳定的不对称涡旋 - 反涡旋平衡态。
