Coulomb Memory Signatures in the Excitonic Optical Stark Effect

Abstract

Differential absorption spectra of high-quality InGaAs quantum wells are presented for various pump detunings and polarization configurations. For low intensity pump pulses tuned well below the exciton a redshift is observed for opposite circularly polarized probe pulses. Microscopic calculations show that this redshift originates from memory effects in the Coulomb-induced excitonic correlations.