Vortex pumps in the crossing lattices regime of highly anisotropic layered superconductors
Vortex pumps in the crossing lattices regime of highly anisotropic layered superconductors
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DOI：
10.1016/j.physc.2005.12.012
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发表时间：
2006-05-15
影响因子：
1.7
通讯作者：
Tamegai, T.
中科院分区：
文献类型：
--
作者：
Cole, D.;Neal, J. S.;Tamegai, T.
现在已经确定，在具有空间不对称的钉扎电位的样品中的涡旋动力学可以导致整流涡旋“二极管”行为。空间的不对称性是不是一个基本的要求控制的涡旋运动，但是，我们证明，涡旋“透镜”是可能的高度各向异性层状超导体的作用下，简单的非时间可逆列车的平面内磁场脉冲。我们的器件依赖于倾斜磁场下Bi_2Sr_2CaCu_2O_8 + δ（BSCCO）单晶中存在的“交叉”煎饼涡旋（PV）和约瑟夫森涡旋（JV）晶格。这两个子晶格之间的吸引力相互作用使得可以通过修改JV晶格来间接操纵PV分布，并且已经提出了许多基于该原理的功能器件。在我们的实验中，BSCCO单晶被放置在霍尔探针阵列上，并在小的面外磁场中冷却到Tc以下。然后将一系列面内场脉冲施加到系统和霍尔阵列的不同元件上，以根据脉冲形状演示PV透镜或反透镜行为。将讨论导致透镜效应的机制，并将结果与分子动力学模拟进行比较。(c)2006 Elsevier B.V.保留所有权利。
It is now well established that vortex dynamics in samples with a spatially asymmetric pinning potential can lead to rectifying vortex 'diode' behaviour. Spatial asymmetry is not a fundamental requirement for the control of vortex motion, however, and we demonstrate that vortex 'lensing' is possible in highly anisotropic layered superconductors simply under the action of non time-reversible trains of in-plane magnetic field pulses. Our devices depend crucially on the existence of 'crossing' pancake vortex (PV) and Josephson vortex (JV) lattices in Bi2Sr2CaCu2O8+delta (BSCCO) single crystals under tilted magnetic fields. An attractive interaction between these two sub-lattices makes it possible to indirectly manipulate the PV distribution by modifying the JV lattice, and a number of functional devices based on this principle have been proposed. In our experiments a BSCCO single crystal is placed on a Hall probe array, and cooled below T-c in a small out-of-plane magnetic field. Trains of sawtooth in-plane field pulses are then applied to the system and different elements of the Hall array used to demonstrate PV lensing or antilensing behaviour, depending on the pulse shape. The mechanism leading to lensing will be discussed and results compared with molecular dynamics simulations. (c) 2006 Elsevier B.V. All rights reserved.