Estellés-Duart Francisco, Ortuño Miguel, Somoza Andrés M, Vinokur Valerii M, Gurevich Alex
Universidad de Murcia, Departamento de Física-CIOyN, Murcia, 30071, Spain.
Argonne National Laboratory, Materials Science Division, Chicago, IL, 60637, USA.
Sci Rep. 2018 Oct 18;8(1):15460. doi: 10.1038/s41598-018-33467-y.
Proliferation of topological defects like vortices and dislocations plays a key role in the physics of systems with long-range order, particularly, superconductivity and superfluidity in thin films, plasticity of solids, and melting of atomic monolayers. Topological defects are characterized by their topological charge reflecting fundamental symmetries and conservation laws of the system. Conservation of topological charge manifests itself in extreme stability of static topological defects because destruction of a single defect requires overcoming a huge energy barrier proportional to the system size. However, the stability of driven topological defects remains largely unexplored. Here we address this issue and investigate numerically a dynamic instability of moving vortices in planar arrays of Josephson junctions. We show that a single vortex driven by sufficiently strong current becomes unstable and destroys superconductivity by triggering a chain reaction of self-replicating vortex-antivortex pairs forming linear of branching expanding patterns. This process can be described in terms of propagating phase cracks in long-range order with far-reaching implications for dynamic systems of interacting spins and atoms hosting magnetic vortices and dislocations.
诸如涡旋和位错等拓扑缺陷的增殖在具有长程序的系统物理中起着关键作用，特别是在薄膜中的超导性和超流性、固体的可塑性以及原子单层的熔化方面。拓扑缺陷由其反映系统基本对称性和守恒定律的拓扑电荷来表征。拓扑电荷的守恒表现为静态拓扑缺陷的极端稳定性，因为破坏单个缺陷需要克服与系统大小成比例的巨大能量障碍。然而，驱动拓扑缺陷的稳定性在很大程度上仍未得到探索。在这里，我们解决这个问题，并通过数值研究约瑟夫森结平面阵列中移动涡旋的动态不稳定性。我们表明，由足够强的电流驱动的单个涡旋会变得不稳定，并通过触发自复制涡旋 - 反涡旋对的链式反应来破坏超导性，这些对形成线性或分支扩展模式。这个过程可以用长程序中传播的相位裂纹来描述，这对承载磁涡旋和位错的相互作用自旋和原子的动态系统具有深远影响。
