title: Photon Cascade from a Single Crystal Phase Nanowire Quantum Dot.
abstract: We report the first comprehensive experimental and theoretical study of the optical properties of single crystal phase quantum dots in InP nanowires. Crystal phase quantum dots are defined by a transition in the crystallographic lattice between zinc blende and wurtzite segments and therefore offer unprecedented potential to be controlled with atomic layer accuracy without random alloying. We show for the first time that crystal phase quantum dots are a source of pure single-photons and cascaded photon-pairs from type II transitions with excellent optical properties in terms of intensity and line width. We notice that the emission spectra consist often of two peaks close in energy, which we explain with a comprehensive theory showing that the symmetry of the system plays a crucial role for the hole levels forming hybridized orbitals. Our results state that crystal phase quantum dots have promising quantum optical properties for single photon application and quantum optics.
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands.
authors.forename: Maaike
authors.initials: M
authors.lastname: Bouwes Bavinck
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands.
authors.forename: Klaus D
authors.initials: KD
authors.lastname: Jöns
authors.affiliation: Instytut Fizyki, UMK , Grudziądzka 5, Toruń 87-100, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Zieliński
authors.affiliation: Laboratoire de Photonique et de Nanostructures, CNRS , route de Nozay , 91460 Marcoussis, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Patriarche
authors.affiliation: Laboratoire de Photonique et de Nanostructures, CNRS , route de Nozay , 91460 Marcoussis, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Harmand
authors.affiliation: Department of Photonics Engineering, Technical University of Denmark , 2800 Kongens Lyngby, Denmark.
authors.forename: Nika
authors.initials: N
authors.lastname: Akopian
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands.|Department of Applied Physics, KTH Royal Institute of Technology , SE-100 44, Stockholm, Sweden.
authors.forename: Val
authors.initials: V
authors.lastname: Zwiller
keywords: Crystal phase quantum dot; InP; nanowire; two-photon cascaded emission; type II transition