Izbrane teme sodobne fizike in matematike
Članek opisuje obnašanje fotonov v topološko netrivialnih materialnih kot analogijo elektronom v topoloških izolatorjih. V prvem teoretičnem delu je razloženih nekaj pojmov povezanih z opisom in razumevanjem topološke svetlobe: uvedem Blochova stanja Berryjevo fazo in ukrivljenost, ki posplošujeta pojem magnetnega potenciala in pretoka na poljubno mnogoterost, Chernovo število, opisan pa je tudi vpliv simetrij na 2D in 3D topološke faze. Drugi del članka pa je namenjen aplikacijam na osnovi topološkega vodenja in kontrole svetlobnih tokov, predvsem na mikroskali, in opisu izbranih eksperimentov.
The article describes the behaviour of photons in topologically nontrivial materials by way of analogy with electrons in topological insulators. In the first theoretical part some key notions regarding understanding of topological light are explained e.g. Bloch states, Berry phase and Berry curvature, the latter two generalizing the concept of vector magnetic potential and flux through an arbitrary manifold, respectively. Furthermore, Chern invariant is defined together with an influence symmetries have on 2D and 3D topological phases. The second part of the article is dedicated upon applications regarding guidance and control of topological light, in particular on a microscale. In the end discussion touches upon some selected experiments in the field.