Giant modulation of resonance Raman scattering from (Cd,Mn)Te quantum wells by secondary illumination

Abstract

Large changes in the intensity of spin-flip Raman signals from (Cd,Mn)Te quantum wells arise under weak additional illumination above the barrier band-gap energy even when the secondary beam is 2 orders of magnitude weaker than the beam used to excite resonant Raman scattering. The behavior is ascribed to changes in the lifetime of the intermediate state in the Raman-scattering process caused by the light-induced alterations in the quantum well carrier density; spin-flip Raman scattering is highly sensitive to this since it is a doubly resonant process.