title: Terahertz excitation of a coherent λ-type three-level system of exciton-polariton modes in a quantum-well microcavity.
abstract: Interactions of few-cycle terahertz pulses with the induced optical polarization in a quantum-well microcavity reveal that the lower and higher exciton-polariton modes together with the optically forbidden 2p-exciton state form a unique Λ-type three-level system. Pronounced nonlinearities are observed via time-resolved strong-terahertz and weak-optical excitation spectroscopy and explained with a fully microscopic theory. The results show that the terahertz pulses strongly couple the exciton-polariton states to the 2p-exciton state while no resonant transition between the two polariton levels is observed.
authors.affiliation: Department of Physics, Oregon State University, Corvallis, Oregon 97331, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Tomaino
authors.forename: A D
authors.initials: AD
authors.lastname: Jameson
authors.forename: Yun-Shik
authors.initials: YS
authors.lastname: Lee
authors.forename: G
authors.initials: G
authors.lastname: Khitrova
authors.forename: H M
authors.initials: HM
authors.lastname: Gibbs
authors.forename: A C
authors.initials: AC
authors.lastname: Klettke
authors.forename: M
authors.initials: M
authors.lastname: Kira
authors.forename: S W
authors.initials: SW
authors.lastname: Koch