Nonlinear response of topological insulators in the terahertz regime
We report that the surface states of Bi2Se3 exhibit strong nonlinear optical responses in the terahertz regime. The third order nonlinear optical conductance can be observed by applying a moderate electric field. The thermal influence on nonlinear optical responses of the surface states of Bi2Se3 is also studied over different temperature and frequency ranges. 2012 IEEE.