Biomedical subjects
Publications and source records attributed to T Flissikowski.
We report on two-photon coherent control of the biexciton state in single Stranski-Krastanov CdSe quantum dots. Clear interference patterns are observed at twice the optical frequency. The decay of the interference contrast is nonexponential and caused by a dynamical inhomogeneous broadening of the energy levels due to long-term fluctuations in the dot environment.
Single-photon interference is observed on the ultranarrow long-term stable exciton resonance of an individual semiconductor quantum dot. This interference is related to the fine-structure splitting and allows direct conclusions about the coherence properties of the exciton. When selectively addressing a particular dot by quasiresonant phonon-assisted excitation, despite a rapid orientation relaxation on a 1-ps time scale, coherence is partly maintained. No significant further decoherence occurs when the ground state is reached until the exciton recombines radiatively (approximately 300 ps).