Magnetoluminescence measurement of Zeeman and exchange interactions of excitons in GaAs/AlGaAs multiple quantum wells

The Zeeman splitting and diamagnetic shift of heavy-hole exciton in GaAs/Al/sub 0.25/Ga/sub 0.25/As multi-quantum wells (MQW) were investigated for various barrier widths by magnetoluminescence up to 30 T at 4.2 K. It is obtained that the diamagnetic shift is independent to the barrier width (L/sub B/), but the effective g-factor becomes smaller as L/sub B/ decreases for a fixed QW width. Also reported is the fine splitting due to the exchange interaction for L/sub B//spl les/50 /spl Aring/.