The effect of wall-induced Ramsey interference on the electromagnetically induced absorption (EIA) in an anti-relaxation coated vapor cell is studied in a four-level closed N-type atomic system. We show that the atomic coherence spontaneously transferred from the excited states to the ground states may interfere via the Ramsey sequence of the moving atoms with decoherence-free wall collisions. The spectral narrowing of the EIA resonance lineshape is induced by the Ramsey effect because of the long lifetime of the spontaneously transferred atomic coherence between the ground states. This calculated Ramsey EIA spectrum is in good agreement with the narrow EIA spectrum obtained experimentally in the anti-relaxation coated vapor cell.The effect of wall-induced Ramsey interference on the electromagnetically induced absorption (EIA) in an anti-relaxation coated vapor cell is studied in a four-level closed N-type atomic system. We show that the atomic coherence spontaneously transferred from the excited states to the ground states may interfere via the Ramsey sequence of the moving atoms with decoherence-free wall collisions. The spectral narrowing of the EIA resonance lineshape is induced by the Ramsey effect because of the long lifetime of the spontaneously transferred atomic coherence between the ground states. This calculated Ramsey EIA spectrum is in good agreement with the narrow EIA spectrum obtained experimentally in the anti-relaxation coated vapor cell.

Optics ExpressApr 10, 20129 citations

Ramsey-like measurement of the decoherence rate between Zeeman sublevels

M. Shuker, Ofer Firstenberg, Yoav Sagi +3 more

Two-photon processes that involve different sublevels of the ground state of an atom, are highly sensitive to depopulation and decoherence within the ground state. For example, the spectral width of electromagnetically induced transparency resonances in a $\ensuremath{\Lambda}$-type system, are strongly affected by the ground-state depopulation and decoherence rates. We present a direct measurement of decay rates between hyperfine and Zeeman sublevels in the ground state of $^{87}\mathrm{Rb}$ vapor. Similar to the relaxation-in-the-dark technique, pumping lasers are used to prealign the atomic vapor in a well-defined quantum state. The free propagation of the atomic state is monitored using a Ramsey-like method. Coherence times in the range $1--10\phantom{\rule{0.3em}{0ex}}\mathrm{ms}$ were measured for room temperature atomic vapor. In the range of the experimental parameters used in this study, the dominant process inducing Zeeman decoherence is the spin-exchange collisions between rubidium atoms.Two-photon processes that involve different sublevels of the ground state of an atom, are highly sensitive to depopulation and decoherence within the ground state. For example, the spectral width of electromagnetically induced transparency resonances in a $\ensuremath{\Lambda}$-type system, are strongly affected by the ground-state depopulation and decoherence rates. We present a direct measurement of decay rates between hyperfine and Zeeman sublevels in the ground state of $^{87}\mathrm{Rb}$ vapor. Similar to the relaxation-in-the-dark technique, pumping lasers are used to prealign the atomic vapor in a well-defined quantum state. The free propagation of the atomic state is monitored using a Ramsey-like method. Coherence times in the range $1--10\phantom{\rule{0.3em}{0ex}}\mathrm{ms}$ were measured for room temperature atomic vapor. In the range of the experimental parameters used in this study, the dominant process inducing Zeeman decoherence is the spin-exchange collisions between rubidium atoms.

arXiv:0807.3110Physical Review ADec 11, 200821 citations

Collision-Induced Ramsey Resonances in Sm Vapor

Egbert Buhr, J. Mlynek

We report on the observation of novel Ramsey-type resonances due to collisional velocity diffusion in atomic samarium vapor in the presence of rare-gas perturbers. The experimental technique uses counterpropagating laser fields and relies on coherent resonance Raman processes to optically excite and detect sublevel coherence within the Doppler-broadened $^{154}\mathrm{Sm}$ $\ensuremath{\lambda}=570.68$-nm $^{7}F_{1}\ensuremath{-}^{7}F_{0}$ transition. The experimental findings are in good agreement with theoretical predictions based on a Fokker-Planck equation; time constants for the collisional thermalization of Sm in He and Ne atmospheres are derived from our data.We report on the observation of novel Ramsey-type resonances due to collisional velocity diffusion in atomic samarium vapor in the presence of rare-gas perturbers. The experimental technique uses counterpropagating laser fields and relies on coherent resonance Raman processes to optically excite and detect sublevel coherence within the Doppler-broadened $^{154}\mathrm{Sm}$ $\ensuremath{\lambda}=570.68$-nm $^{7}F_{1}\ensuremath{-}^{7}F_{0}$ transition. The experimental findings are in good agreement with theoretical predictions based on a Fokker-Planck equation; time constants for the collisional thermalization of Sm in He and Ne atmospheres are derived from our data.

Physical Review LettersSep 15, 198618 citations

Dressed–Atom Approach to Collision–Induced Resonances

P. R. Berman, G. Grynberg

Laser SpectroscopyJan 1, 19890 citations

^{87}\mathrm{Rb}

vapor. Similar to the relaxation-in-the-dark technique, pumping lasers are used to prealign the atomic vapor in a well-defined quantum state. The free propagation of the atomic state is monitored using a Ramsey-like method. Coherence times in the range

1--10\phantom{\rule{0.3em}{0ex}}\mathrm{ms}

were measured for room temperature atomic vapor. In the range of the experimental parameters used in this study, the dominant process inducing Zeeman decoherence is the spin-exchange collisions between rubidium atoms.

^{154}\mathrm{Sm}

$\ensuremath{\lambda}=570.68$-nm $^{7}F_{1}\ensuremath{-}^{7}F_{0}$ transition. The experimental findings are in good agreement with theoretical predictions based on a Fokker-Planck equation; time constants for the collisional thermalization of Sm in He and Ne atmospheres are derived from our data.