Selective branching and converting of topological modes

Abstract

The existence of surface states is a salient feature of topological phases and many of the widely studied physical properties are directly tied to it. Although less explored, a variety of topological phases can be similarly distinguished by their response to localized flux defects, resulting in the binding of modes whose stability can be traced back to that of conventional edge states. The reduced dimensionality of these objects offers the possibility of arranging them in distinct geometries, such as arrays that branch or terminate in the bulk. We show that the prospect of hybridizing the modes in these kinds of channels results in new opportunities in a dynamical context. In particular, we find that certain branches of junctions of such extended defect arrays can be actively biased by manipulating initial conditions. Discussing these physical effects within a generally applicable framework that relates to a variety of established artificial topological materials, such as spring-mass setups and LC circuits, our results offer an avenue to explore and manipulate new transport effects that are rooted in the topological characterization of the underlying system.Received 25 March 2021Revised 8 July 2021Accepted 8 July 2021DOI:https://doi.org/10.1103/PhysRevResearch.3.L032035Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasSymmetry protected topological statesTopological phases of matterPhysical SystemsHoneycomb latticeTechniquesTight-binding modelCondensed Matter, Materials & Applied Physics