arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1302.0747cond-mat.mes-hall
收藏

无序多通道Majorana量子线的准经典理论

Quasiclassical theory of disordered multi-channel Majorana quantum wires

Patrick Neven, Dmitry Bagrets, Alexander Altland

摘要:

多通道自旋轨道量子线在受到磁场作用并与s波超导体近接耦合时,可以支持Majorana态。我们研究的是在无序状态下这些系统会发生什么。受广泛建立的介观超导理论方法的启发,我们发展了一个拉艾伦伯格准经典方法拓扑纳米线有效的限制强自旋轨道耦合。我们发现,“马约拉纳数”,区分状态与马约拉纳费米子(对称类B)和没有马约拉纳(类D),是由产品的两个Pfronans的缺口准经典格林函数固定的右,左终端连接到电线。Eilenberger方程的数值解表明,D类无序量子线容易在局域态密度中形成零能异常(D类杂质谱峰),这与Majorana峰具有相同的关键特征.通过这种方式,我们证实了我们以前的结论的鲁棒性[物理学评论快报。109,227005(2012)],更严格的系统设置。一般来说,我们发现,准经典的方法提供了一个非常有效的手段来解决无序D类超导体的存在和不存在的拓扑结构。

英文摘要:

Multi-channel spin-orbit quantum wires, when subjected to a magnetic field and proximity coupled to s-wave superconductor, may support Majorana states. We study what happens to these systems in the presence of disorder. Inspired by the widely established theoretical methods of mesoscopic superconductivity, we develop a la Eilenberger a quasiclassical approach to topological nanowires valid in the limit of strong spin-orbit coupling. We find that the "Majorana number", distinguishing between the state with Majorana fermion (symmetry class B) and no Majorana (class D), is given by the product of two Pfaffians of gapped quasiclassical Green's functions fixed by right and left terminals connected to the wire. A numerical solution of the Eilenberger equations reveals that the class D disordered quantum wires are prone to the formation of the zero-energy anomaly (class D impurity spectral peak) in the local density of states which shares the key features of the Majorana peak. In this way we confirm the robustness of our previous conclusions [Phys. Rev. Lett. 109, 227005 (2012)] on a more restrictive system setup. Generally speaking, we find that the quasiclassical approach provides a highly efficient means to address disordered class D superconductors both in the presence and absence of topological structures.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑