title: Two-electron linear intersubband light absorption in a biased quantum well.
abstract: We point out a novel manifestation of many-body correlations in the linear optical response of electrons confined in a quantum well. Namely, we demonstrate that along with the conventional absorption peak at a frequency omega close to the intersubband energy delta, there exists an additional peak at frequency h omega approximately = 2delta. This new peak is solely due to electron-electron interactions, and can be understood as excitation of two electrons by a single photon. The actual peak line shape is comprised of a sharp feature, due to excitation of pairs of intersubband plasmons, on top of a broader band due to absorption by two single-particle excitations. The two-plasmon contribution allows us to infer intersubband plasmon dispersion from linear absorption experiments.
authors.affiliation: Department of Physics, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: J
authors.initials: J
authors.lastname: Dai
authors.forename: M E
authors.initials: ME
authors.lastname: Raikh
authors.forename: T V
authors.initials: TV
authors.lastname: Shahbazyan