Photoinduced Hubbard band mixing of a one-dimensional Mott insulator

Based on the nonperturbative many-body time-dependent approach, photoinduced Hubbard band mixing by ultrashort laser pumping is found in a one-dimensional half-filled Hubbard model through the optical conductivity. The photoinduced density of states (DOS) appears below the gap energy (E-g) and is attributed to the metallic weight. In particular, the nonlinear response in the resonant pumping (omega(pu) approximate to E-g) and the linear response in the off-resonant pumping (omega(pu) >> E-g) imply two qualitatively different processes of the photoinduced insulator-metal transition, which is confirmed by the photoemission just after the ultrashort laser irradiation, i.e., the illuminated photoemission. (c) 2007 Elsevier B.V. All rights reserved.