Circular dichroism in higher-order harmonic generation: Heralding topological phases and transitions in Chern insulators
Alexis Chacón, D.S. Kim, W. Zhu, Shane P. Kelly, Alexandre Dauphin, Emilio Pisanty, Andrew Maxwell, Antonio Picón, Marcelo F. Ciappina, Dong Eon Kim, Christopher Ticknor, Avadh Saxena, Maciej Lewenstein
Abstract
The future technological revolution in the production of ultrafast devices lies in the control of materials that will speed-up transistors. The recent discovery of topological states of matter promises a unique opportunity to address this challenge. However, the control and diagnostics of topological materials remain hard to achieve. Here, the authors show an alternative to distinguish a topological phase by its nonlinear-light circular dichroism (CD): the asymmetry of the material-light emissivity while the topological phase is subjected to right-circularly (RCP) and left-circularly polarized (LCP) mid-infrared lasers. This CD exhibits striking distinction in a topological phase, as depicted in the schematic.