Optical nutation in a magnetized semiconductor quantum well structure

Using the semiclassical coherent radiation-semiconductor interaction model, optical nutation has been analysed in a GaAs/AlxGa1-xAs quantum well struc ture (QWS) assumed to be immersed in a moderately strong magnetic field and irradiated by a not-too-strong near band gap resonant femtosecond pulsed T i-sapphire laser. The finite potential well depth of the QWS and the Wannie r-Mott excitonic structure of the crystal absorption edge is taken into acc ount. The excitation intensity is assumed to be below the Mott transition w here the various many-body effects have been neglected with adequate reason ing. Numerical analysis made for a GaAs quantum well of thickness similar t o 100 Angstrom and the confining layers of AlxGa1-xAs with x = 0.3 at inten sity I less than or equal to 5 x10(6) W cm(-2) reveals that the real and im aginary parts of the transient complex-induced polarization are enhanced wi th an increase in the magnetic field and their ringing behaviour confirms t he occurrence of optical nutation in the QWS. (C) 1999 Academic Press.