Topological defect-phase soliton and the pairing symmetry of a two-band superconductor: role of the proximity effect.
Topological defect-phase soliton and the pairing symmetry of a two-band superconductor: role of the proximity effect.
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DOI：
10.1103/physrevlett.109.227003
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发表时间：
2012-03
影响因子：
8.6
通讯作者：
V. Vakaryuk;V. Stanev;Wei‐Cheng Lee;A. Levchenko
中科院分区：
文献类型：
--
作者：
V. Vakaryuk;V. Stanev;Wei‐Cheng Lee;A. Levchenko
我们提出了一种促进相位孤子存在的机制，相位孤子是在具有 s(+-) 型配对的双带超导体的超导间隙的相对相位中形成的拓扑缺陷。该机制利用了传统 s 波超导体的邻近效应，有利于双带超导体的相位对齐，在 s(+-) 配对的情况下，在不邻近的情况下会发生 π 偏移。在强接近的情况下，这种效应可用于将孤子的能量降低到无孤子态的能量以下，从而使孤子热力学稳定。基于这一观察，我们考虑了一种适用于稳定和亚稳态孤子的实验装置，可用于区分铁基多带超导体中的 ss(+-) 和 s(++) 配对类型。
We suggest a mechanism which promotes the existence of a phase soliton--a topological defect formed in the relative phase of superconducting gaps of a two-band superconductor with s(+-) type of pairing. This mechanism exploits the proximity effect with a conventional s-wave superconductor which favors the alignment of the phases of the two-band superconductor which, in the case of s(+-) pairing, are π shifted in the absence of proximity. In the case of a strong proximity such an effect can be used to reduce the soliton's energy below the energy of a soliton-free state, thus making the soliton thermodynamically stable. Based on this observation we consider an experimental setup, applicable for both stable and metastable solitons, which can be used to distinguish between ss(+-) and s(++) types of pairing in the iron-based multiband superconductors.