Resonant multiphoton electron emission from a quantum well

Abstract
Direct observation of resonant multiphoton electron emission from a quantum well is reported. Photocurrent measurements as a function of photon energy and polarization in an AlInAs/GaInAs quantum well heterostructure demonstrate that electrons are photoexcited out of the wells via a three‐photon transition into a resonant state mainly localized in the barriers. This effect is strongly enhanced by the presence of intermediate energy levels.