Berlin 2005 – wissenschaftliches Programm
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Q: Quantenoptik und Photonik
Q 3: Poster Quanteninformation, -kommunikation und Quantencomputer
Q 3.2: Poster
Freitag, 4. März 2005, 11:00–12:30, Poster HU
A Novel Scheme for the Generation of Single Photons of alternating Polarization — •Tatjana Wilk, Holger Specht, Axel Kuhn, and Gerhard Rempe — Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, D-85748 Garching
In the last two years, single-photon generation from atom-cavity systems has been successfully demonstrated in several experiments [1-3]. In these experiments, photons are produced by Raman transitions between electronic or hyperfine levels, and a time-consuming repumping to the initial state is required between two emissions. Here, we propose a new scheme where a Raman transition is driven between two Zeemann sublevels, mF=±1, of a F=1 hyperfine state of a single atom. A cavity couples these states to a F’=0 hyperfine level of an electronically exited state. In addition, a magnetic field is applied that lifts the degeneracy of the mF=±1 levels. Therefore a Raman transition can be driven in one direction only, i.e. from mF=+1 to mF=−1 (or vice versa), by exposing the atom to a laser pulse tuned to the respective resonance. If, e.g., a laser pulse of frequency f− resonantly drives the mF=−1 to mF=+1 transition, a σ− photon is generated. A subsequent laser pulse of frequency f+ driving the transition in the opposite sense then generates a σ+-photon. This scheme requires no repumping between successive emissions and produces a stream of photons with alternating σ+ and σ− polarization.
[1] Kuhn et al. Phys. Rev. Lett. 89, 67901 (2002)
[2] McKeever et al. Sience 303, 1992 (2004)
[3] Keller et al. Nature 431, 1075 (2004)