First-principle real-time simulation for dynamical Franz-Keldysh effect

Otobe, Tomohito; Shinohara, Yasushi*; Sato, Shunsuke*; Yabana, Kazuhiro*

We calculate the modulation of the optical properties of a diamond under the intense static fields and intense mid-infrared (MIR) light fields employing the time-dependent density functional theory (TDDFT). We solve the time-dependent Khon-Sham equation with real-time and -space method under time-dependent vector fields. Our results reproduce the exponentially tail of absorption below the band gap and the Franz-Keldysh oscillation above the band gap. We found that the absorption below the gap oscillates with the electric field and the adiabatic approximation is valid for higher laser intensity.