Stark shift and g-factor tuning in nanowires with Rashba effect

• Energy spectra of electrons in nanowires are calculated in the weak Rashba regime.
• For in-plane magnetic field, the Stark shift is rigid and the g-factor cannot be tuned.
• Perpendicular magnetic fields add lateral displacement to the Stark shift.
• The g-factor can be tuned by external electric field in this case.
• The tuning of the g-factor is linear and unique for all subbands at high fields.

We report on the Stark shift of the energy subbands and the possibility of tuning the g-factor of electrons in nanowires subjected to external magnetic field. The electric field is applied along the direction of quantum confinement. Our analysis is based on numerical and perturbation calculations in the weak Rashba regime. For in-plane magnetic fields, the Stark shift is rigid and depends on the square of the electric field. Such rigid shift results in a field independent g-factor. Perpendicular magnetic fields induce a similar Stark shift accompanied by a lateral displacement of the energy spectra that is linear in the electric field. In this case, the g-factor shows square dependence on weak electric fields that varies with the subband index. However, in strong electric fields, the g-factor becomes subband independent and varies linearly with the field.