Line-broadening studies of highly excited Rb atoms (A)

Cedomil Vadla, Vlasta Horvatić, Kay Niemax

Recent absorption measurements of the self-broadening of Rb principal series lines [C. H. Greene, E. L. Hamilton, H. Crowell, C. Vadla, and K. Niemax, Phys. Rev. Lett. 97, 233002 (2006)] verified the existence of minima in highly excited long-range potentials of ${\text{Rb}}_{2}$ which were predicted theoretically as bound Rydberg molecule [C. H. Greene, A. S. Dickinson, and H. R. Sadeghpour, Phys. Rev. Lett. 85, 2458 (2000)]. The present paper reports on the extension of these experimental studies to principal series lines of K broadened by K as well as Cs broadened by Cs. In addition, the broadening of some lower members of the K, Rb, and Cs principal line series due to heteroatomic interactions was investigated. The analysis of the measured satellite structures in the quasistatic line wings and their comparison to the previously published analogous data for ${\text{Rb}}^{\ensuremath{\ast}}+\text{Rb}$ system lead to the conclusion that one can expect existence of potential minima in homo- and heteroatomic alkali-metal ${A}^{\ensuremath{\ast}}+B$ systems in a wide range of principal quantum numbers, starting with K, Rb, and Cs excited to the third resonance states. The positions and strengths of the satellite structures indicate that the potential minima are due to scattering of the valence electron by ground-state perturbers.

Petar Grujić

Kazunori Nakayama, Masatoshi Misono, T. Kohmoto +2 more

Summary form only given. To understand the fundamental properties of an atom, precise measurement of the atomic resonance frequency is important. The main factor that restricts the precision is the spectral broadening. Spectral narrowing by recurrent use of free decay signal in magnetic resonance was proposed and demonstrated in the ground state of Rb atoms. In the present report we apply this technique to the measurement of the hyperfine frequency in the excited state. This is a sublevel spectroscopy with recurrent excitation, where the atomic response is iteratively used as the next excitation. The hyperfine spectra of the excited state /sup 2/P/sub 3/2/ of the D/sub 2/ transition in Rb atoms, whose line width is much narrower than the natural line width, was observed and the hyperfine constants of the excited state were determined precisely.

M. S. Dimitrijević, Sylvie Sahal-Bréchot

Petar Grujić

Andrey V. Loboda, Alexander V. Glushkov, О. Yu. Khetselius +4 more

Preliminary results of calculating the broadening of spectral lines of excited atoms induced by ultralong‐ range (100 Bohr radii) interactions in a cold gas of Rb atoms within the “own pressure” approximation and perturbation theory formalism are presented.