Today on the archive
Thu Sep 21 08:49:37 EST 2006
- [physics/0609160]
- Title: Photonic mode density effects on single-molecule fluorescence blinking
- Authors: F. D. Stefani, K. Vasilev, N. Bocchio, F. Gaul, A. Pomozzi, M. Kreiter
- Abstract: We investigated the influence of the photonic mode density (PMD) on the triplet dynamics of individual chromophores on a dielectric interface by comparing their response in the presence and absence of a nearby gold film. Lifetimes of the excited singlet state were evaluated in ordet to measure directly the PMD at the molecules position. Triplet state lifetimes were simultaneously determined by statistical analysis of the detection time of the fluorescence photons. The observed singlet decay rates are in agreement with the predicted PMD for molecules with different orientations. The triplet decay rate is modified in a fashion correlated to the singlet decay rate. These results show that PMD engineering can lead to an important suppression of the fluorescence, introducing a novel aspect of the physical mechanism to enhance fluorescence intensity in PMD-enhancing systems such as plasmonic devices.
- Comment: basic idea is the emission rate of an excited molecule can be modified if the molecule is close to a metal surface, due to the excitation of plasmons (bound electron-photon excitations) in the metal. The same effect is observed in cold atom experiments where the atoms are close to a metal surface (eg a chip trap such as in Ed Hinds' group at Imperial College), and is an important decoherence mechanism for scalable quantum computing.
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