Electronic phase conversion by photoinjection of excitations

We theoretically discuss the photoinduced electronic phase conversion mediated by the electronic interactions, using a phenomenological model of bistable electrons and the modified Hubbard model. We focus on the dynamics after photoexcitation into one of the (meta)stable states of the multistable electronic systems. When small amount of excitations are injected, they merely induce small oscillations in the electronic states. On the other hand, when larger amounts of excitations than a threshold value are injected, they successfully induce large oscillations in the electronic states, which we can regard as the phase conversions. Conditions for induction of the phase conversion are clarified; such induction by photoinjection of a small amount of excitations is possible when the mixing of the two electronic states is large in the initial (meta)stable state.