Stuttgart 2012 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 9: Quanteneffekte: Interferenz und Korrelationen

Q 9.6: Vortrag

Montag, 12. März 2012, 15:15–15:30, V7.01

Enhanced lifetime of positronium atoms via collective radiative effects — •Ni Cui, Mihai Macovei, Karen Z. Hatsagortsyan, and Christoph H. Keitel — Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany

Positronium (Ps) is a hydrogen-like atom comprised of an electron and the positron. The ground states of Ps are not stable and the system will annihilate by γ emission. Such short lifetimes give rise to evident difficulties in accumulating Ps atoms and achieving Ps BEC, and the simulated annihilation from Ps BEC may set up a route towards a γ-ray laser [1]. Hereby, we proposed a method to manipulate the annihilation dynamics of a dense gas of Ps atoms employing superradiant and subradiant spontaneous emission. The annihilation dynamics can be controlled by the density of the gas and the intensity of the driving strong resonant laser field. We found that the annihilation lifetime of an ensemble of Ps atoms can be enhanced more than hundred times by trapping the atoms in the excited state via collective radiative effects in the resonant laser and cavity fields [2].

[1] P. M. Platzman and A. P. Mills, Jr., Phys. Rev. B 49, 454 (1994); D. B. Cassidy, et al. Phys. Rev. Lett. 106, 023401 (2011).

[2] Ni Cui, Mihai Macovei, Karen Z. Hatsagortsyan, and Christoph H. Keitel, arXiv:1112.1621v1.