title: The polarization response in InAs quantum dots: theoretical correlation between composition and electronic properties.
abstract: III-V  growth and surface conditions strongly influence the physical structure and resulting optical properties of self-assembled quantum dots (QDs). Beyond the design of a desired active optical wavelength, the polarization response of QDs is of particular interest for optical communications and quantum information science. Previous theoretical studies based on a pure InAs QD model failed to reproduce experimentally observed polarization properties. In this work, multi-million atom simulations are performed in an effort to understand the correlation between chemical composition and polarization properties of QDs. A systematic analysis of QD structural parameters leads us to propose a two-layer composition model, mimicking In segregation and In-Ga intermixing effects. This model, consistent with mostly accepted compositional findings, allows us to accurately fit the experimental PL spectra. The detailed study of QD morphology parameters presented here serves as a tool for using growth dynamics to engineer the strain field inside and around the QD structures, allowing tuning of the polarization response.
authors.affiliation: Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland. usman@alumni.purdue.edu
authors.forename: Muhammad
authors.initials: M
authors.lastname: Usman
authors.forename: Vittorianna
authors.initials: V
authors.lastname: Tasco
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Todaro
authors.forename: Milena
authors.initials: M
authors.lastname: De Giorgi
authors.forename: Eoin P
authors.initials: EP
authors.lastname: O'Reilly
authors.forename: Gerhard
authors.initials: G
authors.lastname: Klimeck
authors.forename: Adriana
authors.initials: A
authors.lastname: Passaseo
mesh_terms: D001152:Arsenicals / Q000737:chemistry*; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D007204:Indium / Q000737:chemistry*; D008422:Materials Testing; D008956:Models, Chemical; D008968:Molecular Conformation; D010316:Particle Size; D045663:Quantum Dots
chemical_list: D001152:Arsenicals; D007204:Indium; C076773:indium arsenide