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Q: Quantenoptik

Q 323: Quanteneffekte II

Q 323.5: Vortrag

Mittwoch, 6. März 2002, 17:30–17:45, HS 01/E02

State reduction in resonance fluorescence with spectral resolution — •Vyacheslav Shatokhin — MPI für Physik komplexer Systeme, Nöthnitzer Str. 38, D-01187 Dresden, Germany — Institute of Physics of NASB, Fr. Skaryna ave. 70, 220072 Minsk, Belarus

The problem of a reduced atomic state in resonance fluorescence is revisited by considering the state of the atom following detection of a photon passed through an interference filter. Due to the energy-time uncertainty relation, any detected photon has been emitted at a random time in the past. As a consequence, the reduced atomic state in the narrowband case can be defined only as the average state, unlike the broadband detection case when emission instants may be easily recovered from instants of detection.

Two properties of the reduced atomic state amenable to experimental verification are discussed. First, for fixed filter bandwidth, and regardless of the frequency of the detected photon, the Bloch vector of the reduced state lies in a hemisphere y≥ 0, on a disc obtained by a cut of the Bloch sphere defined by a plane orthogonal to the y-z plane. Another property emerges in the limit of well-separated spectral lines of the resonance fluorescence spectrum. In that case, inversion of the average atomic state may be observed, as a consequence of quantum interference between spontaneous transitions between the dressed states of the atom.