Topological excitations in a kagome magnet

• DOI: 10.1038/ncomms5815
• Publication Date: 2014-09-08T13:27:15Z
• Authors: Manuel Pereiro; Dmitry Yudin; Jonathan Chico; Corina Etz; Olle Eriksson; Anders Bergman
• Keywords: Skyrmion; Chirality; Annihilation; Point reflection

It is shown here that a Kagom�� magnet, with Heisenberg and Dzyaloshinskii-Moriya interactions causes non trivial topological and chiral magnetic properties. Chirality---that is, left or right handedness---is a very important concept in a broad range of scientific areas, and particularly, in condensed matter physics. Inversion symmetry breaking relates chirality with skyrmions, that are protected field configurations with particle-like and topological properties. Here, the reported numerical simulations and theoretical considerations reveal that the magnetic excitations of the Kagom�� magnet can both be of regular bulk magnon character, as well as, having a non-trivial topological nature. We also find that under special circumstances, skyrmions emerge as excitations, having stability even at room temperature. Chiral magnonic edge states of a Kagom�� magnet offer, in addition, a promising way to create, control and manipulate skyrmions. This has potential for applications in spintronics, magnonics and skyrmionics, i.e., for information storage or as logic devices based on the transportation and control of these particles. Collisions between these particle-like excitations are found to be elastic in the skyrmion-skyrmion channel, albeit without mass-conservation for an individual skyrmion. Skyrmion-antiskyrmion collisions are found to be more complex, where annihilation and creation of these objects have a distinct non-local nature.<br/>15 pages, 10 figures<br/>