TCM Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
Phys Rev Lett. 2013 May 24;110(21):216803. doi: 10.1103/PhysRevLett.110.216803. Epub 2013 May 22.
We present a powerful and general approach to describe the coupling of Majorana fermions to external leads, of interacting or noninteracting electrons. Our picture has the Klein factors of bosonization appearing as extra Majorana fermions hybridizing with the physical ones. We demonstrate the power of this approach, analyzing a highly nontrivial SO(M) Kondo problem arising in topological superconductors with M Majorana-lead couplings, allowing for arbitrary M and for conduction electron interactions. Mapping the problem on a quantum Brownian motion model we find robust non-Fermi liquid behavior, even for Fermi liquid leads, and a quantum phase transition between insulating and Kondo regimes when the leads form Luttinger liquids. In particular, for M=4 we find a stable realization of the two-channel Kondo fixed point. Obtaining the linear conductance at low temperatures, we predict transport signatures of this Majorana-Kondo-Luttinger physics.
我们提出了一种强大而通用的方法来描述马约拉纳费米子与外部引线的耦合，包括相互作用或非相互作用的电子。我们的图像具有玻色化的克莱因因子，表现为与物理马约拉纳费米子杂化的额外马约拉纳费米子。我们通过分析在具有 M 个马约拉纳-引线耦合的拓扑超导体中出现的高度非平凡的 SO(M) 近藤问题，展示了这种方法的强大之处，该问题允许任意 M 和传导电子相互作用。通过将问题映射到量子布朗运动模型上，我们发现了稳健的非费米液体行为，即使对于费米液体引线也是如此，并且当引线形成 Luttinger 液体时，在绝缘和近藤区域之间存在量子相变。特别是，对于 M=4，我们发现了两通道近藤固定点的稳定实现。在低温下获得线性电导率时，我们预测了这种马约拉纳-近藤-Luttinger 物理的输运特征。
