Laser-irradiated Kondo insulators : Controlling Kondo effect and topological phases

Abstract

We theoretically investigate the nature of laser-irradiated Kondo insulators. Using Floquet theory and slave boson approach, we study a periodic Anderson model and derive an effective model which describes the laser-irradiated Kondo insulators. In this model, we find two generic effects induced by laser light. One is the dynamical localization, which suppresses hopping and hybridization. The other is the laser-induced hopping and hybridization, which can be interpreted as a synthetic spin-orbit coupling or magnetic field. The first effect drastically changes the behavior of the Kondo effect. Especially, the Kondo effect under laser light qualitatively changes its character depending on whether the hybridization is on-site or off-site. The second effect triggers topological phase transitions. In topological Kondo insulators, linearly polarized laser light realizes phase transitions between trivial, weak topological, and strong topological Kondo insulators. Moreover, circularly polarized laser light breaks time-reversal symmetry and induces Weyl semimetallic phases. Our results pave the new way to dynamically control the Kondo effect and topological phases in heavy fermion systems. We also discuss experimental setups to detect the signatures.