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| Creator | Title | Description | Subject | Date | ||
|---|---|---|---|---|---|---|
| 1 |
 | Vardeny, Zeev Valentine | Cooperative emission in ∏-conjugated polymer thin films | Picosecond dynamics of exciton emission and absorption have been studied in neat thin films of a variety of poly (phenylene vinylene) derivatives. We found that the stimulated emission band of 120 nm width and ~1 ns duration, which is observed at low exciton density n, collapses at n > 1017 cm-3 int... | Pi-conjugated polymers; Poly (phenylene vinylene) derivatives; PPV derivatives; Cooperative emission | 1997-01 |
| 2 |
 | Vardeny, Zeev Valentine; Ehrenfreund, Eitan A. | Dispersion of resonant Raman scattering in ∏-conjugated polymers: role of the even parity excitons | Resonant Raman scattering dispersion of the most strongly coupled phonon frequencies with the excitation laser photon energy is measured in terms of a dispersion rate parameter D and quantified in a variety of p conjugated polymer films. D was found to be large in nonluminescent polymers and small i... | Resonant raman scattering; Even parity excitons | 1997-09 |
| 3 |
 | Vardeny, Zeev Valentine; Gellermann, Werner | Exciton dynamics in soluble poly(p-phenylene-vinylene): toward an ultrafast excitonic switch | We have applied a variety of ps transient and cw optical techniques to elucidate the dynamics, absorption, and emission properties of excitons in soluble derivatives of poly(p-phenylene vinylene) neat films and dilute solutions. We found that the photogenerated singlet excitons in both films and sol... | Exciton dynamics; Excitonic switch | 1997-06 |
| 4 |
 | Vardeny, Zeev Valentine | Transient spectroscopy of Frenkel and charge transfer excitons in α-sexithienyl films | Photoexcitations dynamics are investigated in a-sexithienyl nanocrystalline films using transient photomodulation in a spectral range from 0.4 to 2.5 eV and time domain from 200 fs to 50 ms. We identify intrachain and interchain excitations. The former are even parity excitons with ultrafast dynami... | Transient spectroscopy; Excitons; Frenkel exciton; Charge transfer exciton; Transient photomodulation | 1997-10 |
| 5 |
 | DeTar, Carleton | Which chiral symmetry is restored in high temperature quantum chromodynamics? | Sigma models for the high temperature phase transition in quantum chromodynamics suggest that at high temperature the SU(Nf) X 3 SU(Nf) chiral symmetry becomes exact, but the anomalous axial U(1) symmetry need not be restored. In numerical lattice simulations, traditional methods for detecting symme... | Chiral symmetry; Staggered fermions; Phase transitions | 1997-01 |
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