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Coherent transient nonlinear optical spectroscopic studies of single semiconductor quantum dots: Applications to quantum information processing.

dc.contributor.authorLi, Xiaoqin
dc.contributor.advisorSteel, Duncan G.
dc.date.accessioned2016-08-30T15:26:57Z
dc.date.available2016-08-30T15:26:57Z
dc.date.issued2003
dc.identifier.urihttp://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqm&rft_dat=xri:pqdiss:3106109
dc.identifier.urihttps://hdl.handle.net/2027.42/123893
dc.description.abstractThe focus of the thesis is nonlinear transient optical properties and coherent control of single interface fluctuation quantum dots (QD's). When single exciton and biexciton resonances were driven by strong resonant laser pulses, Rabi oscillations of these transitions were observed in the differential transmission (DT) geometry. These results extend the concept of coherent control to the limit of single quantum confined systems in solids and have important implications for the feasibility of building quantum information processing devices using semiconductor QD's. Exciton Rabi oscillations are equivalent to arbitrary single-bit operations. The pulsed control of the exciton-biexciton transition is utilized as the optical operation for building a two-bit controlled rotational gates (CROT) in a single QD. A fidelity of 0.79 was obtained from numerical evaluation of the gate operation itself assuming typical decay parameters measured from these dots. Next, the nonradiative quantum coherence between two orthogonally polarized excitons confined in a single QD was studied. By using pulses with large enough bandwidth and the proper polarization, two exciton states are simultaneously excited. The quantum beats between the two exciton states were temporally resolved as the relative phase between the two dipole oscillations changed. It was found that the nonradiative coherence time is limited by the lifetimes of the excitons involved even in the strong field regime. In the basis of the pseudo-spin Bloch vectors of exciton transitions, the total wavefunction following the pulsed excitation is an entangled state, i.e. the wavefunction is non-factorizable. Finally, the quantum coherence between the biexciton, exciton, and the crystal ground states was studied in a novel quantum beat experiment, where the oscillations only existed when the pump and probe pulses overlapped in time. Laser pulses generated after a passive pulse shaper with just enough bandwidth to cover both the exciton and biexciton transitions were used in this experiment. The appearance of the beats is indicative of a reasonably long coherence time between the biexciton and other states even in the presence of strong pulsed excitations.
dc.format.extent157 p.
dc.languageEnglish
dc.language.isoEN
dc.subjectApplications
dc.subjectCoherent
dc.subjectNonlinear
dc.subjectOptical
dc.subjectProcessing
dc.subjectQuantum Information
dc.subjectRabi Oscillations
dc.subjectSemiconductor Quantum Dots
dc.subjectSingle
dc.subjectSpectroscopic
dc.subjectStudies
dc.subjectTransient
dc.titleCoherent transient nonlinear optical spectroscopic studies of single semiconductor quantum dots: Applications to quantum information processing.
dc.typeThesis
dc.description.thesisdegreenamePhDen_US
dc.description.thesisdegreedisciplineCondensed matter physics
dc.description.thesisdegreedisciplineOptics
dc.description.thesisdegreedisciplinePure Sciences
dc.description.thesisdegreegrantorUniversity of Michigan, Horace H. Rackham School of Graduate Studies
dc.description.bitstreamurlhttp://deepblue.lib.umich.edu/bitstream/2027.42/123893/2/3106109.pdf
dc.owningcollnameDissertations and Theses (Ph.D. and Master's)


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