Theory of photoionization of two-electron quantum dots in the resonance region in THz and mid-IR fields

In this work we present an ab initio nonperturbative theory for the description of the two-electron dynamics of a spherical quantum dot (QD) in THz and mid-IR ultrashort laser fields. We have approximated the QD's confinement potential to have a Gaussian-like spatial dependence and have calculated its electronic structure and photoionization one-electron cross sections with an ab initio configuration-interaction approach. We have also calculated the ionization yields following the interaction with a laser pulse by numerically solving the time-dependent Schrodinger equation. All results show a strong dependence on the dot size. We have also identified resonances, of the Fano-type, in the photoionization spectrum with properties varying along with the QD size.