Evaluation of magnetic penetration depth and surface resistance of superconducting thin films using coplanar waveguides
Evaluation of magnetic penetration depth and surface resistance of superconducting thin films using coplanar waveguides
复制标题
使用共面波导评估超导薄膜的磁穿透深度和表面电阻
DOI：
10.1109/77.402973
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发表时间：
1995
影响因子：
1.8
通讯作者：
K. Enpuku
中科院分区：
文献类型：
--
作者：
K. Yoshida;K. Watanabe;T. Kisu;K. Enpuku
我们提出了一种利用共面波导的动态电感测量来估算超导薄膜的磁穿透深度和表面电阻的方法。该方法利用共面波导谐振器，测量了动感引起的谐振频率随温度的变化关系。将观测数据与采用保角变换技术的解析表达式进行比较，给出了磁穿透深度的值。用这种方法得到的NbN薄膜的磁穿透深度与用电阻率和临界温度的脏极限理论估算的结果符合得很好。将该方法应用于YBaCuO谐振器，得到了c轴取向薄膜的磁穿透深度/SPL波长/(0)=266 nm。利用双流体模型还表明，薄膜的表面电阻可以从品质因数和动力学电感两个方面来估算。在3.8 GHz频率下测得剩余表面电阻Rs(0)=20/splµ//spl欧米茄；
We have proposed a method to evaluate the magnetic penetration depth and the surface resistance of superconducting thin films from the kinetic inductance measurement using coplanar waveguides. The method utilizes the coplanar waveguide resonator where the temperature dependence of the resonant frequency due to the kinetic inductance is measured. Comparison between the observed data and an analytical expression using a conformal mapping technique gives the value of the magnetic penetration depth. The magnetic penetration depth of NbN thin films obtained in this way is shown to be in excellent agreement with that estimated from the dirty limit theory using resistivity and critical temperature. By applying this method to a YBaCuO resonator, we obtained the magnetic penetration depth /spl lambda/(0)=266 nm for a c-axis oriented film. Using the two-fluid model it is also shown that the surface resistance of the film can be evaluated from the quality factor and the kinetic inductance. We obtained the residual surface resistance Rs(0)=20 /spl mu//spl Omega/ at a frequency of 3.8 GHz.<<ETX>>