title: Exciton-polariton gas as a nonequilibrium coolant.
abstract: Using angle-resolved Raman spectroscopy, we show that a resonantly excited ground-state exciton-polariton fluid behaves like a nonequilibrium coolant for its host solid-state semiconductor microcavity. With this optical technique, we obtain a detailed measurement of the thermal fluxes generated by the pumped polaritons. We thus find a maximum cooling power for a cryostat temperature of 50 K and below where optical cooling is usually suppressed, and we identify the participation of an ultrafast cooling mechanism. We also show that the nonequilibrium character of polaritons constitutes an unexpected resource: each scattering event can remove more heat from the solid than would be normally allowed using a thermal fluid with normal internal equilibration.
authors.affiliation: Institut Néel, Université Grenoble Alpes and CNRS, B.P. 166, 38042 Grenoble, France.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Klembt
authors.affiliation: Institut Néel, Université Grenoble Alpes and CNRS, B.P. 166, 38042 Grenoble, France.
authors.forename: Emilien
authors.initials: E
authors.lastname: Durupt
authors.affiliation: LPMMC, Université Grenoble Alpes and CNRS, B.P. 166, 38042 Grenoble, France.
authors.forename: Sanjoy
authors.initials: S
authors.lastname: Datta
authors.affiliation: University of Bremen, P.O. Box 330440, 28334 Bremen, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Klein
authors.affiliation: Institut Néel, Université Grenoble Alpes and CNRS, B.P. 166, 38042 Grenoble, France.
authors.forename: Augustin
authors.initials: A
authors.lastname: Baas
authors.affiliation: Laboratoire FOTON, CNRS, INSA de Rennes, 35708 Rennes, France.
authors.forename: Yoan
authors.initials: Y
authors.lastname: Léger
authors.affiliation: University of Bremen, P.O. Box 330440, 28334 Bremen, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Kruse
authors.affiliation: University of Bremen, P.O. Box 330440, 28334 Bremen, Germany.
authors.forename: Detlef
authors.initials: D
authors.lastname: Hommel
authors.affiliation: LPMMC, Université Grenoble Alpes and CNRS, B.P. 166, 38042 Grenoble, France.
authors.forename: Anna
authors.initials: A
authors.lastname: Minguzzi
authors.affiliation: Institut Néel, Université Grenoble Alpes and CNRS, B.P. 166, 38042 Grenoble, France.
authors.forename: Maxime
authors.initials: M
authors.lastname: Richard