Current-assisted thermally activated flux liberation in ultrathin nanopatterned NbN superconducting meander structures
Current-assisted thermally activated flux liberation in ultrathin nanopatterned NbN superconducting meander structures
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DOI：
10.1103/physrevb.81.024502
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发表时间：
2010-01-01
影响因子：
3.7
通讯作者：
Semenov, A.
中科院分区：
文献类型：
--
作者：
Bartolf, H.;Engel, A.;Semenov, A.
我们目前的结果从一个广泛的研究由溅射NbN超导纳米线的波动现象。纳米尺度的线被制造成曲折的形式，并在接近0.4T（c）（0）的恒定温度T下操作。超导状态被驱动接近电子相变附近的临界一个高偏置电流。足够强度的波动暂时驱动曲折结构的一部分进入正常导电状态，这可以被记录为纳秒持续时间的电压脉冲。我们考虑了三种不同的模型（涡反涡对，涡边缘障碍，和相滑移中心）来解释实验数据。只有热激发的涡，无论是通过解开的涡-antivortex对或涡克服边缘障碍，导致一个令人满意的和一致的描述所有的测量。
We present results from an extensive study of fluctuation phenomena in superconducting nanowires made from sputtered NbN. Nanoscale wires were fabricated in form of a meander and operated at a constant temperature T approximate to 0.4T(c)(0). The superconducting state is driven close to the electronic phase transition by a high bias current near the critical one. Fluctuations of sufficient strength temporarily drive a section of the meander structure into the normal-conducting state, which can be registered as a voltage pulse of nanosecond duration. We considered three different models (vortex-antivortex pairs, vortex edge barriers, and phase-slip centers) to explain the experimental data. Only thermally excited vortices, either via unbinding of vortex-antivortex pairs or vortices overcoming the edge barrier, lead to a satisfactory and consistent description for all measurements.