Switching chiral solitons for algebraic operation of topological quaternary digits

Abstract

Chiral objects can be found throughout nature(1-4); in condensed matter chiral objects are often excited states protected by a system's topology. The use of chiral topological excitations to carry information has been demonstrated, where the information is robust against external perturbations(5,6). For instance, reading, writing, and transfer of binary information have been demonstrated with chiral topological excitations in magnetic systems, skyrmions(7-14), for spintronic devices(13-19). The next step is logic or algebraic operations of such topological bits(20-22). Here, we show experimentally the switching between chiral topological excitations or chiral solitons of different chirality in a one-dimensional electronic system with Z(4) topological symmetry(23,24). We found that a fast-moving achiral soliton merges with chiral solitons to switch their handedness. This can lead to the realization of algebraic operation of Z(4) topological charges(25). Chiral solitons could be a platform for storage and operation of robust topological multi-digit information.