Quantum waveguide theory of Andreev spectroscopy in multiband superconductors: The case of iron pnictides
Quantum waveguide theory of Andreev spectroscopy in multiband superconductors: The case of iron pnictides
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DOI：
10.1103/physrevb.79.174529
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发表时间：
2009-05-01
影响因子：
3.7
通讯作者：
Sacramento, P. D.
中科院分区：
文献类型：
--
作者：
Araujo, M. A. N.;Sacramento, P. D.
本文讨论了正常金属与多带超导体之间的Andreev反射问题。适当的匹配条件的波函数在界面上的量子波导理论的基础上建立这些系统的扩展。超导体的不同频带之间的干扰效应表现在电导和FeAs超导体的情况下，特别考虑，在最近提出的有效的两个频带模型的框架内，在符号反转的s波配对的情况下。通过表面Andreev束缚态的共振传输被发现，以及破坏性的干涉效应，产生零的电导在法向入射。这两种效应都发生在非零偏置电压下。
The problem of Andreev reflection between a normal metal and a multiband superconductor is addressed. The appropriate matching conditions for the wave function at the interface are established on the basis of an extension of quantum waveguide theory to these systems. Interference effects between different bands of the superconductor manifest themselves in the conductance and the case of FeAs superconductors is specifically considered, in the framework of a recently proposed effective two-band model, in the sign-reversed s-wave pairing scenario. Resonant transmission through surface Andreev bound states is found as well as destructive interference effects that produce zeros in the conductance at normal incidence. Both these effects occur at nonzero bias voltage.