title: Ghost Branch Photoluminescence From a Polariton Fluid Under Nonresonant Excitation.
abstract: An expanding polariton condensate is investigated under pulsed nonresonant excitation with a small laser pump spot. Far above the condensation threshold we observe a pronounced increase in the dispersion curvature, with a subsequent linearization of the spectrum and strong luminescence from a ghost branch orthogonally polarized with respect to the linearly polarized condensate emission. Polarization of both branches is understood in terms of spin-dependent polariton-polariton scattering. The presence of the ghost branch has been confirmed in time-resolved measurements. The effects of disorder and dissipation in the photoluminescence of polariton condensates and their excitations are discussed.
authors.affiliation: Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Pieczarka
authors.affiliation: Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Syperek
authors.affiliation: Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Dusanowski
authors.affiliation: Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Misiewicz
authors.affiliation: Technische Physik, University of Würzburg and Wilhelm-Conrad-Röntgen-Research Center for Complex Material Systems (RCCM), Am Hubland, D-97074 Würzburg, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Langer
authors.affiliation: Technische Physik, University of Würzburg and Wilhelm-Conrad-Röntgen-Research Center for Complex Material Systems (RCCM), Am Hubland, D-97074 Würzburg, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Forchel
authors.affiliation: Technische Physik, University of Würzburg and Wilhelm-Conrad-Röntgen-Research Center for Complex Material Systems (RCCM), Am Hubland, D-97074 Würzburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Kamp
authors.affiliation: Technische Physik, University of Würzburg and Wilhelm-Conrad-Röntgen-Research Center for Complex Material Systems (RCCM), Am Hubland, D-97074 Würzburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Schneider
authors.affiliation: Technische Physik, University of Würzburg and Wilhelm-Conrad-Röntgen-Research Center for Complex Material Systems (RCCM), Am Hubland, D-97074 Würzburg, Germany.|SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom.
authors.forename: Sven
authors.initials: S
authors.lastname: Höfling
authors.affiliation: Spin Optics Laboratory, Saint Petersburg State University, 1 Ulianovskaya, 198504 St. Petersburg, Russia.|Physics and Astronomy School, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom.
authors.forename: Alexey
authors.initials: A
authors.lastname: Kavokin
authors.affiliation: Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Sęk