Collective intersubband excitations in a magnetic field

Abstract Inelastic light scattering from modulation doped GaAs/Al x Ga 1−x As quantum wells has been used to study collective intersubband excitations in magnetic fields. With the magnetic field tilted with respect to the sample normal, there is coupling between the perpendicular and parallel motions such that combined intersubband-cyclotron resonance transitions are observed. In this geometry we observe anticrossing behavior between the combined resonances and the collective charge- and spin-density excitations. Comparison with theory yields excellent agreement.