title: Biexciton gain and the Mott transition in GaAs quantum wires.
abstract: Optical gain and the Mott transition in GaAs quantum wires were studied via simultaneous measurements of absorption and photoluminescence (PL). We observed well-separated PL peaks assigned to excitons (X) and biexcitons (XX) even at densities where optical gain existed. A sharp optical gain first appeared when the XX peak overtook the X peak, indicating the gain origin of biexciton-exciton population inversion. The XX peak eventually changed to a broad peak of plasma, and a broad gain due to plasma was observed as the Mott transition was completed.
authors.affiliation: Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Hayamizu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yoshita
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Akiyama
authors.forename: C Z
authors.initials: CZ
authors.lastname: Ning
authors.forename: Loren N
authors.initials: LN
authors.lastname: Pfeiffer
authors.forename: Ken W
authors.initials: KW
authors.lastname: West