Physical Review Letters
Two-photon absorption in GaAs quantum wires
R. Cingolani, Maria Antonietta Lepore, Raffaele Tommasi, Ida Maria Catalano, H. Lage, D. Heitmann, Klaus Ploog, A. Shimizu, H. Sakaki, T. Ogawa
Abstract
We have investigated the polarization-dependent two-photon absorption in GaAs/AlGaAs quantum wires. The anisotropic selection rules of the multiphoton absorption process are exploited to study the one-dimensional 2p exciton states and the transitions between quantum wire subbands of different quantum numbers (\ensuremath{\Delta}${\mathit{n}}_{\mathit{y}}$\ensuremath{\ne}0 selection rule). The deviations from the selection rules derived for the strict one-dimensional case are discussed, and depend on the actual quasi-one-dimensional character of the excitonic wave functions.