Vortex dynamics in a NbN film studied by terahertz spectroscopy
Vortex dynamics in a NbN film studied by terahertz spectroscopy
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DOI：
10.1103/physrevb.79.174525
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发表时间：
2009-05
影响因子：
3.7
通讯作者：
Y. Ikebe;R. Shimano;M. Ikeda;T. Fukumura;M. Kawasaki
中科院分区：
文献类型：
--
作者：
Y. Ikebe;R. Shimano;M. Ikeda;T. Fukumura;M. Kawasaki
利用太赫兹时域光谱研究了涡旋动力学对NbN超导薄膜高频电导率的影响。在不使用Kramers-Kronig分析的情况下测定了高达7 T的混合态的复电导率。实验获得的电导率谱进行了分析，考虑从准粒子在旋涡中的贡献，也从旋涡动力学。为了将局域场效应纳入混合态超导体的高频电磁响应中，我们将麦克斯韦-加内特理论与自洽双流体模型相结合，得到了有效电导率的表达式。的涡流的体积分数显示的线性依赖于所施加的磁场，预期的波超导体，考虑到磁通流电阻率。
We have investigated the effect of vortex dynamics on high-frequency conductivity of a superconducting NbN film by using terahertz time-domain spectroscopy. The complex conductivity of the mixed state up to 7 T is determined without using Kramers-Kronig analysis. The experimentally obtained conductivity spectra are analyzed by considering the contribution from quasiparticles in vortices and also from the vortex dynamics. To include the local-field effect in the high-frequency electromagnetic responses of mixed-state superconductors, we combined the Maxwell-Garnett theory with a self-consistent two-fluid model and obtained the expression for the effective conductivity. The volume fraction of the vortices shows the linear dependence on the applied magnetic field, as expected for-wave superconductors, by taking into account the flux-flow resistivity.