Electromagnetically induced transparency in an inhomogeneously broadenedΛtransition with multiple excited levels

Abstract

Electromagnetically induced transparency (EIT) has mainly been modelled for three-level systems. In particular, a considerable interest has been dedicated to the Λ-configuration, with two ground states and one excited state. However, in the alkali-metal atoms, which are commonly used, hyperfine interaction in the excited state introduces several levels which simultaneously participate in the scattering process. When the Doppler broadening is comparable with the hyperfine splitting in the upper state, the three-level Λ model does not reproduce the experimental results. Here we theoretically investigate the EIT in a hot vapor of alkali-metal atoms and demonstrate that it can be strongly reduced due to the presence of multiple excited levels. Given this model, we also show that a well-designed optical pumping enables to significantly recover the transparency.

Thermometry of ultracold atoms by electromagnetically induced transparency

“…In our experiment this corresponds to an upper temperature limit of several hundred mK. For even higher temperatures, the spectra become more complicated [20]. In addition, the large two-photon Doppler shift is detrimental to the spectral resolution.…”

“…However, for a description at larger precision (i.e., as desired for EIT-based thermometry) we will include also some additional off-resonant couplings (dark gray states in Fig. 1) [20]. There are two additional excited states |4 (corresponding to |F = 0,m F = 0 ) and |5 (corresponding to |F = 2,m F = 0 ) in the vicinity of state |3 .…”

A scaling law for light scattering from dense and cold atomic ensembles

“…For instance, such gases can be used in quantum information science, in which cold clouds are promising objects for quantum memory problems (1)(2)(3)(4)(5). Theoretical results have also suggested that a high degree of vacuum squeezing of near resonance radiation may be obtained in such optically dense media through the action of the polarization self rotation effect (6)(7)(8).…”

Quantitative analysis of the transient response of the refractive index to conditions of electromagnetically induced transparency

“…To estimate the confidence one may have in a simple threelevel model we also need to examine to what degree one can map the complex multilevel hyperfine structure of 87 Rb to this reduced level scheme [35]. To do so, we need to take into account the different strengths of the various hyperfine transitions.…”