Coherence properties of single self assembled quantum dots [Elektronische Ressource] / von Timur Flissikowski

Coherence properties of single self-assembledquantum dotsD I S S E R T A T I O Nzur Erlangung des akademischen Gradesdoctor rerum naturalium(Dr. rer. nat.)im Fach Physikeingereicht an derMathematisch-Naturwissenschaftlichen Fakult¨at Ider Humboldt-Universitat¨ zu BerlinvonDipl.-Phys. Timur Flissikowskigeb. 13. August 1972 in BerlinPrasiden¨ t der Humboldt-Universitat¨ zu Berlin:Prof. Dr. MlynekDekan der Mathematisch-Naturwissenschaftlichen Fakultat I:¨Prof. Buckhout, PhDGutachter:1. Prof. Dr. F. Henneberger (HU Berlin)2. Prof. Dr. O. Benson (HU Berlin)3. Priv.-Doz. Dr. A. Hoffmann (TU Berlin)eingereicht am: 14. Mai 2004Tag der mundlic¨ hen Prufung:¨ 16. November 2004iAbstractSemiconductor quantum dots (QD) have attracted considerable interest dur-ing the past years as possible candidates for quantum information processing.Due to the confinement potential in such structures, the density of states in asingle QD is discrete. If the states are well separated in energy the coupling totheenvironmentisexpectedtobesmaller, implyingthatcoherenceismaintainedduring the exciton lifetime. In the present work CdSe in ZnSe QDs are used.Inthisthesis,twokindsofcoherencephenomena,reflectingthetimeevolutionof such a quantum system, are studied by use of optical methods. The firstphenomenaisoptical coherence. Inthiscase, anexcitedstatewhichisradiativelycoupled to a ground state interacts with an external electro-magnetic field.