Strong-field nonlinear response of quantum dots

Summary form only given. Recent studies have been carried out on the resonant response from single interface fluctuation quantum dots. Such a discrete-level model yields unique signatures under strong resonant driving, including Rabi oscillations. To date, Rabi oscillations (excluding microcavity studies) have only been reported for two-dimensional excitonic systems. We present data showing the nonlinear response from an ensemble of interface fluctuation quantum dots. This data is consistent with Rabi oscillations for moderate driving fields (that is, for /spl Theta//spl sim/2/spl pi/, where /spl Theta/ is the pulse area). The sample under investigation is a single thin (62 /spl Aring/) GaAs/Al/sub 0.3/Ga/sub 0.7/As quantum well grown with growth interruptions and is studied at 5 K. The laser is tuned to the lower energy excitonic resonance, corresponding to an inhomogeneously broadened distribution of excitons localized due to well width fluctuations. The time-integrated PL is collected with a spectrometer tuned 2.5 meV below the excitonic resonance.