Santos Luiz H, Hughes Taylor L
Department of Physics and Institute for Condensed Matter Theory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801-3080, USA.
Phys Rev Lett. 2017 Mar 31;118(13):136801. doi: 10.1103/PhysRevLett.118.136801. Epub 2017 Mar 27.
We explore a scenario where local interactions form one-dimensional gapped interfaces between a pair of distinct chiral two-dimensional topological states-referred to as phases 1 and 2-such that each gapped region terminates at a domain wall separating the chiral gapless edge states of these phases. We show that this type of T junction supports pointlike fractionalized excitations obeying parafermion statistics, thus implying that the one-dimensional gapped interface forms an effective topological parafermionic wire possessing a nontrivial ground state degeneracy. The physical properties of the anyon condensate that gives rise to the gapped interface are investigated. Remarkably, this condensate causes the gapped interface to behave as a type of anyon "Andreev reflector" in the bulk, whereby anyons from one phase, upon hitting the interface, can be transformed into a combination of reflected anyons and outgoing anyons from the other phase. Thus, we conclude that while different topological orders can be connected via gapped interfaces, the interfaces are themselves topological.
我们探讨了一种情形，即局部相互作用在一对不同的手性二维拓扑态（称为相1和相2）之间形成一维带隙界面，使得每个带隙区域终止于分隔这些相的手性无隙边缘态的畴壁。我们表明，这种类型的T型结支持服从准费米子统计的点状分数化激发，这意味着一维带隙界面形成了具有非平凡基态简并度的有效拓扑准费米子线。研究了产生带隙界面的任意子凝聚体的物理性质。值得注意的是，这种凝聚体使带隙界面在体相中表现为一种任意子“安德烈夫反射器”，即来自一个相的任意子在撞击界面时，可以转化为来自另一相的反射任意子和出射任意子的组合。因此，我们得出结论，虽然不同的拓扑序可以通过带隙界面连接，但界面本身是拓扑性的。
