Vortex-Antivortex Lattices in Superconducting Films with Magnetic Pinning Arrays
Vortex-Antivortex Lattices in Superconducting Films with Magnetic Pinning Arrays
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DOI：
10.1103/physrevlett.93.267006
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发表时间：
2004-12
影响因子：
2
通讯作者：
M. Milošević;F. Peeters
中科院分区：
文献类型：
--
作者：
M. Milošević;F. Peeters
无磁头当超导薄膜(SC)被平面外磁化磁点(MD)晶格覆盖时，我们发现了丰富多样的涡旋结构。随着磁阵周期的增加，涡旋被限制在MD区域，并且反涡旋成规则晶格，规则晶格通过向单点涡旋-反涡旋构型的几个二级转变而弛豫。随着MD磁化强度的增加，涡旋-反涡旋对的产生由一个单一的量--超流速度控制。我们证明了由于磁通产生的涡旋-反涡旋对和超导电流，样品中的临界电流如果暴露在均匀的外磁场中，实际上是增加的，这与常规的超导行为相反。我们解释了进一步的实验意义，例如磁场诱导的超导电性。
No HeadingWe found a rich variety of vortex structures when a thin superconducting film (SC) is covered with a lattice of out-of-plane magnetized magnetic dots (MDs). The vortices are confined to the MD regions, and antivortices nucleate into regular lattices which relax through several second order transitions towards single-dot vortex-antivortex configurations with increasing period of the magnetic array. Creation of vortex-antivortex pairs with increasing MD-magnetization is controlled by a single quantity - the superfluid velocity. We demonstrate that due to the vortex-antivortex pairs and the supercurrents induced by the MDs, the critical current in the sample actually increases if exposed to a homogeneous external magnetic field, contrary to conventional SC behavior. We explain further experimental implications, such as the magnetic field-induced-superconductivity.