Transfer-matrix approach to multiband josephson junctions
Transfer-matrix approach to multiband josephson junctions
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DOI：
10.1103/physrevb.75.014507
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发表时间：
2006-08
影响因子：
3.7
通讯作者：
S. Graser;T. Dahm
中科院分区：
文献类型：
--
作者：
S. Graser;T. Dahm
研究了多个能带对约瑟夫森结性质的影响。特别是，我们重点研究了双间隙超导体二硼化镁。我们给出了一种描述两个电极之间点接触处隧道效应的形式，将转移矩阵方法推广到多个带。给出了一个简单的模型来确定不同能带之间的有效跳跃幅度作为电极偏置角的函数。我们计算了不同取向的$N\text{\ensuremath{-}}I\text{\ensuremath{-}}S$和$S\text{\ensuremath{-}}I\text{\ensuremath{-}}S$接触在高透明度和低透明度下的临界电流和伏安特性。我们发现，带间隧穿过程随着错向角的增大而变得越来越重要。这反映在隧道极限和多次安德列夫反射的差异隧道电导的某些特征上。
We study the influence of multiple bands on the properties of Josephson junctions. In particular, we focus on the two gap superconductor magnesium diboride. We present a formalism to describe tunneling at a point contact between two $\mathrm{Mg}{\mathrm{B}}_{2}$ electrodes generalizing the transfer-matrix approach to multiple bands. A simple model is presented to determine the effective hopping amplitudes between the different energy bands as a function of the misorientation angle of the electrodes. We calculate the critical current and the current-voltage characteristics for $N\text{\ensuremath{-}}I\text{\ensuremath{-}}S$ and $S\text{\ensuremath{-}}I\text{\ensuremath{-}}S$ contacts with different orientation for junctions with both high and low transparency. We find that interband tunneling processes become increasingly important with increasing misorientation angle. This is reflected in certain features in the differential tunneling conductance in both the tunneling limit as well as for multiple Andreev reflections.