Coherent dynamics of interwell excitons in GaAs/AlxGa1−xAs superlattices

V. Mizeikis, D. Birkedal, W. Langbein, J. M. Hvam
1997 Physical Review B (Condensed Matter)  
Coherent exciton dynamics in a GaAs/Al x Ga 1Ϫx As narrow-miniband superlattice is studied by spectrally resolved transient four-wave mixing. Coherent optical properties of the investigated structure are found to be strongly affected by the existence of two different heavy-hole excitonic states. One of them, the 1s heavy-hole exciton, is almost identical to the same state in noninteracting quantum wells, while the other, the heavy-hole interwell exciton, is composed of an electron and a heavy
more » ... ctron and a heavy hole in adjacent wells. The interwell exciton leads to a resonant enhancement in the four-wave mixing spectra and exhibits quantum beats with the 1s heavy-hole exciton. The dephasing of the interwell exciton is one order of magnitude faster than that of the heavy-hole exciton and is mostly due to intensity-independent scattering mechanisms.
doi:10.1103/physrevb.55.7743 fatcat:djkwf2vxyjgunijxnf5fpd5zmi