Subgap pumping of antiferromagnetic Mott insulators: photoexcitation mechanisms and applications

Recent technological advances have enabled increasingly stronger ultrafast driving of correlated insulators at frequencies below their charge excitation gap. Experimental access to new pump-probe regimes challenges the conventional understanding of such materials' nonequilibrium behavior under subgap driving, and motivates further theoretical study of the carrier photoexcitation mechanisms. Here, we employ a time-dependent Gaussian approach to study the behavior of a 2D repulsive Hubbard model at half filling, under driving by strong ac electric fields. We show that dynamical suppression of the Mott gap gives rise to a rich landscape of photoexcitation regimes, and discuss connections with experimental observations.