Band structure of quantum wells under crossed electric and magnetic fields

We investigate the band structure in GaAs quantum wells in the presence of an electric field applied along the growth direction (z) and a magnetic field perpendicular to it. The strong coupling between heavy and light holes gives rise to a nonquadratic behavior of the hole states as a function of the magnetic field. The presence of the electric field introduces new transitions by breaking the z symmetry and by coupling with the magnetic field. The Kramers degeneracy is also lifted by the external fields. The results are discussed in terms of band-to-band transitions. © 1988 The American Physical Society.