title: Magnetic polaron on dangling-bond spins in CdSe colloidal nanocrystals.
abstract: Non-magnetic colloidal nanostructures can demonstrate magnetic properties typical for diluted magnetic semiconductors because the spins of dangling bonds at their surface can act as the localized spins of magnetic ions. Here we report the observation of dangling-bond magnetic polarons (DBMPs) in 2.8-nm diameter CdSe colloidal nanocrystals (NCs). The DBMP binding energy of 7 meV is measured from the spectral shift of the emission lines under selective laser excitation. The polaron formation at low temperatures occurs by optical orientation of the dangling-bond spins (DBSs) that result from dangling-bond-assisted radiative recombination of spin-forbidden dark excitons. Modelling of the temperature dependence of the DBMP-binding energy and emission intensity shows that the DBMP is composed of a dark exciton and about 60 DBSs. The exchange integral of one DBS with the electron confined in the NC is ∼0.12 meV.
authors.affiliation: Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany.|IEMN, CNRS, Avenue Henri Poincaré, 59491 Villeneuve-d'Ascq, France.
authors.forename: Louis
authors.initials: L
authors.lastname: Biadala
authors.affiliation: Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany.|Rzhanov Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Shornikova
authors.affiliation: Ioffe Institute, Russian Academy of Sciences, 194021 Saint Petersburg, Russia.
authors.forename: Anna V
authors.initials: AV
authors.lastname: Rodina
authors.affiliation: Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany.|Ioffe Institute, Russian Academy of Sciences, 194021 Saint Petersburg, Russia.
authors.forename: Dmitri R
authors.initials: DR
authors.lastname: Yakovlev
authors.affiliation: Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Siebers
authors.affiliation: Department of Inorganic and Physical Chemistry, Universiteit Gent, 9000 Ghent, Belgium.
authors.forename: Tangi
authors.initials: T
authors.lastname: Aubert
authors.affiliation: Laboratoire de Physique et d'Etude des Matériaux, PSL Research University, CNRS UMR 8213, Sorbonne Universités UPMC Université Paris 06, ESPCI Paris, 10 rue Vauquelin, 75005 Paris, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Nasilowski
authors.affiliation: Department of Inorganic and Physical Chemistry, Universiteit Gent, 9000 Ghent, Belgium.
authors.forename: Zeger
authors.initials: Z
authors.lastname: Hens
authors.affiliation: Laboratoire de Physique et d'Etude des Matériaux, PSL Research University, CNRS UMR 8213, Sorbonne Universités UPMC Université Paris 06, ESPCI Paris, 10 rue Vauquelin, 75005 Paris, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Dubertret
authors.affiliation: Naval Research Laboratory, Washington DC 20375, USA.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Efros
authors.affiliation: Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany.|Ioffe Institute, Russian Academy of Sciences, 194021 Saint Petersburg, Russia.
authors.forename: Manfred
authors.initials: M
authors.lastname: Bayer