Screening and band bending effects in the Stark control of electrons at interfaces (SCELI)

Recently, we developed a general laser control scheme, i.e., the Stark control of electrons at interfaces (SCELI), based on Stark shifts, that is able to manipulate the electron dynamics at material interfaces [A. J. Garz\'on-Ram\'{\i}rez and I. Franco, Phys. Rev. B 98, 121305 (2018)]. Here, we investigate how SCELI is influenced by the band bending effects introduced by interfacial dipoles and by the laser screening due to the polarization response of the material. For this, we follow the quantum dynamics of a model one-dimensional tight-binding semiconductor-semiconductor heterojunction driven by nonresonant few-cycle laser pulses of intermediate intensity. Band bending effects are introduced through an interfacial electrostatic potential term dictated by the depletion approximation of a neutral $p\text{\ensuremath{-}}n$ junction. In turn, screening effects are captured through the general boundary conditions of the field vectors at interfaces dictated by Maxwell's equations. For field amplitudes where SCELI dominates (${E}₀\ensuremath{\le}0.55$ V/\AA{} in the model), laser screening leads to a 46% reduction of the effect that can be partially compensated by increasing the intensity of the incident field. Surprisingly, band bending mildly affects SCELI. When both band bending and screening are considered simultaneously, the charge transfer is reduced, on average, 40% for ${E}₀\ensuremath{\le}0.46$ V/\AA{}. Overall, we observe that screening and band bending change the magnitude of SCELI but leave the underlying mechanism for electron transfer intact.