V001 / JSI / T3


On 22 December 2014 the journal Nature Physics published an article entitled Light-controlled topological charge and a Nematic Liquid Crystal , written by Maryam Nikkhou, Miha Škarabot, Simon Čopar, Miha Ravnik, Slobodan Žumer and Igor Muševič, from the Department for Solid-State Physics (F5) of the Jožef Stefan Institute and the Faculty of Mathematics and Physics, University of Ljubljana. Their paper describes experiments in which a strong laser light is used to create and stabilize a pair of topological defects in liquid crystals formed by a defect and an anti-defect or a "particle" and an "antiparticle". The picture shows the liquid crystal, as seen under a microscope, only a few milliseconds after the laser pulse. This pulse leads to the formation of a dense network of topological defects, from which eventually pairs of topological defects are formed. This is reminiscent of the Kibble-Zurek mechanism for the production of monopoles in cosmology. This means that by using the theory of the dynamics of the provisions for annihilation and basic topological rules we can observe the mechanisms for the production topological charge.