ИСТИНА

we present and analyze the results on the generation of the third terahertz harmonic in topological insulators with a chalcogen-ordered tetradymite structure. An analysis of the experimental results indicates the possibility of obtaining higher conversion efficiency to the third harmonic in topological insulator than even in graphene. A consistent kinetic theory of third harmonic generation in topological insulators has been developed. The generation of terahertz radiation in a photoconductive antenna based on a thin fi lm of topological insulator is experimentally demonstrated and numerically calculated.