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 (ω_pu≈E_g; ω_pu is the pumping laser energy and E_g 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 (ω_pu⪢E_g) where the rigid band picture is valid. The photoemission response after the ultrashort pulse confirms our finding.