Nonlinear Zeeman splitting of magnetoexcitons in c-plane wurtzite GaN-based quantum wells

We present a theoretical description of excitonic spectra in GaN-based quantum wells in a wide range of magnetic fields taking into account built-in strain and electric fields, and valence band mixing due to the quantum well confinement. Our calculations performed for the GaN/AlGaN quantum wells reveal a nonlinear behavior of the excitonic Zeeman splitting on magnetic field. We have determined that the low magnetic field g-factor dependence on the quantum well width shows a steplike variation due to the reordering of the light-and heavy-hole valence subbands. Sharp change of the g factor is also predicted for InGaN/GaN quantum wells grown on a virtual metamorphic InGaN substrate.