@article{HartmannSchreiberStreitwolfetal.1995, author = {Hartmann, Michael and Schreiber, Michael and Streitwolf, H.-W. and Mukamel, Shaul}, title = {Nonlinear optical excitations in femtosecond spectroscopy of conjugated polymers}, series = {Journal of Luminescence}, volume = {66-67}, journal = {Journal of Luminescence}, url = {http://nbn-resolving.de/urn:nbn:de:0298-opus4-5795}, pages = {97 -- 101}, year = {1995}, abstract = {We have investigated the optical excitation of solitons and charge transfer excitons in polymer chains by solving the equations of motion for the reduced density matrix and the lattice displacement simultaneously in time. Electron-phonon coupling leads to polaron-exciton formation which can be identified in transient pump-probe signals.}, language = {en} } @inproceedings{HartmannTakahashiMukameletal.1995, author = {Hartmann, Michael and Takahashi, Akira and Mukamel, Shaul and Schreiber, Michael}, title = {Soliton and exciton effects in femtosecond spectroscopy of conjugated polymers}, series = {International Conference on Excitonic Processes in Condensed Matter}, booktitle = {International Conference on Excitonic Processes in Condensed Matter}, year = {1995}, abstract = {We introduce a concept which allows to study the nonlinear optical response of conjugated polymers taking into account many-body effects of the excitation process. The formation of charge transfer excitons and the creation of lattice distortions are studied in short polymer chains by solving the self consistent equations of motion for the reduced single electron density matrix and the lattice displacement. The coupling of electronic motions to lattice dynamics gives rise to the formation of excitonic polarons, which can be identified in the femtosecond pump-probe signal.}, language = {en} } @article{HartmannChernyakMukamel1995, author = {Hartmann, Michael and Chernyak, Vladimir Y. and Mukamel, Shaul}, title = {Real-space coupled-oscillator approach to the radiative decay of conjugated polymers}, series = {Physical Review B}, volume = {52}, journal = {Physical Review B}, number = {4}, url = {http://nbn-resolving.de/urn:nbn:de:0298-opus4-5813}, pages = {Keine Angabe - No details -- Keine Angabe - No details}, year = {1995}, abstract = {The optical response of conjugated polymers is calculated using a one-dimensional tight-binding model with Coulomb interactions, and adopting the multipolar form for the electromagnetic field Hamiltonian. By formulating the problem using the reduced single-electron density matrix and its evolution in Liouville space, we obtain a real-space description for the elementary electronic excitations. A unified expression for the linear response including radiative decay, which is valid for arbitrary chain size compared with the optical wavelength, is described. For small sizes it shows exciton confinement effects on the radiative decay and for larger sizes it fully incorporates polariton effects.}, language = {en} } @inproceedings{HartmannTakahashiMukameletal.1994, author = {Hartmann, Michael and Takahashi, Akira and Mukamel, Shaul and Schreiber, Michael}, title = {Soliton and Exciton Effects in Femtosecond Pump Probe Spectroscopy of Conjugated Polymers}, series = {International Conference on Excitonic Processes in Condensed Matter, Darwin}, booktitle = {International Conference on Excitonic Processes in Condensed Matter, Darwin}, url = {http://nbn-resolving.de/urn:nbn:de:0298-opus4-5859}, year = {1994}, abstract = {Keine Angabe - No details}, language = {en} } @inproceedings{HartmannTakahashiMukamel1994, author = {Hartmann, Michael and Takahashi, Akira and Mukamel, Shaul}, title = {Soliton and Exciton Effects on Photoexcited Conjugated Polymers}, series = {2nd International Topical Conference on Optical Probes of Conjugated Polymers and Fullerenes, Salt Lake City}, booktitle = {2nd International Topical Conference on Optical Probes of Conjugated Polymers and Fullerenes, Salt Lake City}, year = {1994}, abstract = {Keine Angabe - No details}, language = {en} } @article{HartmannMukamel1993, author = {Hartmann, Michael and Mukamel, Shaul}, title = {Femtosecond four wave mixing spectroscopy of conjugated polymers}, series = {The Journal of Chemical Physics}, volume = {99}, journal = {The Journal of Chemical Physics}, number = {3}, url = {http://nbn-resolving.de/urn:nbn:de:0298-opus4-5897}, pages = {1597 -- 1606}, year = {1993}, abstract = {Time-resolved four wave mixing (4WM) signals of conjugated polymers are calculated using a density matrix approach and the Hartree-Fock approximation. The influence of the Coulomb interaction as well as size effects on the nonlinear optical response are examined. For the H{\"u}ckel model (no Coulomb interaction), quantum beats due to the coherent excitation of several band states are found for small sizes, and photon echo-like behavior is obtained for infinite size. The Coulomb interaction changes the nature of the response and gives rise to a broad delayed signal whose temporal profile is determined by the dephasing time.}, language = {en} } @inproceedings{WangTakahashiHartmannetal.1993, author = {Wang, Hong Xiang and Takahashi, Akira and Hartmann, Michael and Mukamel, Shaul}, title = {Quantum Confinement and Nonlinear Optical Response of Conjugated Molecules}, series = {International Symposia on Optoelectronic Packaging and Interconnects, Los Angeles}, booktitle = {International Symposia on Optoelectronic Packaging and Interconnects, Los Angeles}, url = {http://nbn-resolving.de/urn:nbn:de:0298-opus4-5911}, year = {1993}, abstract = {Keine Angabe - No details}, language = {en} }