Magnetic slowdown of topological edge states

具有奇时间反演对称性的拓扑绝缘体的绝对连续边谱

Absolutely continuous edge spectrum of topological insulators with an odd time-reversal symmetry

该研究证明受奇时间反演对称性保护的非平凡二维拓扑绝缘体具有绝对连续边谱，借助Wold分解的时间反演对称版本分离出其弹道边缘模，为相关拓扑绝缘体的边缘态性质提供了理论证明。

沿弯曲界面的拓扑边缘谱

Topological edge spectrum along curved interfaces

本文研究拓扑绝缘体边界几何形状对导电性的影响，证明边界将平面分成两个含任意大球区域时必为导体，而可嵌入条带内的拓扑绝缘体则未必存在导电边界模式。

Topological squashed entanglement: nonlocal order parameter for one-dimensional topological superconductors

Identifying entanglement-based order parameters characterizing topological systems, in particular topological superconductors and topological insulators, has remained a major challenge for the physics of quantum matter in the last two decades. Here we show that the end-to-end, long-distance, bipartite squashed entanglement between the edges of a many-body system, defined in terms of the edge-to-edge quantum conditional mutual information, is the natural nonlocal order parameter for topological superconductors in one dimension as well as in quasi one-dimensional geometries. For the Kitaev chain…

Edge-following topological states

We prove that Chern insulators have topologically protected edge states which not only propagate unidirectionally along a straight line boundary, but also swerve around arbitrary-angled corners and geometric imperfections of the material boundary. This is a physical manifestation of the index theory of certain semigroup operator algebras.

The $K$-theoretic bulk-edge correspondence for topological insulators

We study the application of Kasparov theory to topological insulator systems and the bulk-edge correspondence. We consider observable algebras as modelled by crossed products, where bulk and edge systems may be linked by a short exact sequence. We construct unbounded Kasparov modules encoding the dynamics of the crossed product. We then link bulk and edge Kasparov modules using the Kasparov product. Because of the anti-linear symmetries that occur in topological insulator models, real $C^*$-algebras and $KKO$-theory must be used.

Observation of edge solitons in topological trimer arrays

We report the experimental observation of nonlinear light localization and edge soliton formation at the edges of fs-laser written trimer waveguide arrays, where transition from non-topological to topological phases is controlled by the spacing between neighboring trimers. We found that, in the former regime, edge solitons occur only above a considerable power threshold, whereas in the latter one they bifurcate from linear states. Edge solitons are observed in a broad power range where their propagation constant falls into one of the topological gaps of the system, while partial delocalization…