Photoinduced Hubbard band mixing due to ultrafast laser irradiation of a one-dimensional Mott insulator

Based on the nonperturbative many-body time-dependent approach, photoinduced Hubbard band mixing by ultrashort laser pulse is found in a one-dimensional half-filled Hubbard model through the optical conductivity. The nonlinear development of Drude-like (metallic) weight in the resonant optical pumping (ωpu ≈ Eg; ωpu is the pumping laser energy and Eg is the gap energy) indicates reconstruction and mixing of the upper and lower Hubbard bands, in contrast to the case of linear development in off-resonant pumping (ωpu ≈Eg) where the rigid band picture is valid. The photoemission response after the ultrashort pulse confirms our finding.