I. Barjoseph et al., 4-WAVE-MIXING IN MODULATION-DOPED GAAS QUANTUM-WELLS UNDER STRONG MAGNETIC-FIELDS, Physica status solidi. b, Basic research, 188(1), 1995, pp. 457-463
Time-resolved four-wave mixing is used to study electron scattering in
modulation-doped GaAs quantum wells in high magnetic fields up to 8 T
. A strong increase in dephasing times in strong magnetic fields is ob
served and attributed to a decrease in the scattering rates relative t
o zero field. An early time signal in high magnetic field is found, wh
ich is due to a polarization interaction process. A strong enhancement
of the signal at the absorption edge is measured which is attributed
to the Fermi edge singularity.