The technique of Doppler-free two-photon spectroscopy was used to measure rates for line broadenings and frequency shifts of Rydberg levels with pressure. Measurements were made of spectra of $^{2}\mathrm{S}$ and $^{2}\mathrm{D}$ states (with n\ensuremath{\sim}10--40) for ${\mathrm{Rb}}^{\mathrm{*}\mathrm{*}}$ +Rb and ${\mathrm{K}}^{\mathrm{*}\mathrm{*}}$ +K, and of $^{2}\mathrm{S}$ states (with n=14--29) for ${\mathrm{K}}^{\mathrm{*}\mathrm{*}}$ +Rb. Large oscillations are observed in both broadening and shift rates for n\ensuremath{\sim}20--30 in all series except for the $^{2}\mathrm{D}$ series in ${\mathrm{Rb}}^{\mathrm{*}\mathrm{*}}$ +Rb. Overall rates for broadening and shift are compared with a theory based on the ``free-electron'' model. The observed oscillations are inconsistent with theories based on the resonance scattering of the Rydberg electron by the perturbing atom. A possible alternative mechanism related to interference in l-mixing collisions is suggested.The technique of Doppler-free two-photon spectroscopy was used to measure rates for line broadenings and frequency shifts of Rydberg levels with pressure. Measurements were made of spectra of $^{2}\mathrm{S}$ and $^{2}\mathrm{D}$ states (with n\ensuremath{\sim}10--40) for ${\mathrm{Rb}}^{\mathrm{*}\mathrm{*}}$+Rb and ${\mathrm{K}}^{\mathrm{*}\mathrm{*}}$+K, and of $^{2}\mathrm{S}$ states (with n=14--29) for ${\mathrm{K}}^{\mathrm{*}\mathrm{*}}$+Rb. Large oscillations are observed in both broadening and shift rates for n\ensuremath{\sim}20--30 in all series except for the $^{2}\mathrm{D}$ series in ${\mathrm{Rb}}^{\mathrm{*}\mathrm{*}}$+Rb. Overall rates for broadening and shift are compared with a theory based on the ``free-electron'' model. The observed oscillations are inconsistent with theories based on the resonance scattering of the Rydberg electron by the perturbing atom. A possible alternative mechanism related to interference in l-mixing collisions is suggested.

Physical Review AJan 1, 198735 citations

Atomic excitation and spectral line broadening

Leonid A. Vainshtein, Igor I Sobel'man, E. A. Iukov

Moscow Izdatel NaukaJan 1, 197911 citations

Interaction between spin polarized alkali atoms

Victor A. Kartoshkin

Collisions of alkali-metal atoms in the ground state with the electron spin S = 1/2 are accompanied by exchange of electron coordinates between colliding particles, which leads to polarization transfer between them (i.e., to the well-known phenomenon of spin exchange). In addition, along with the polarization transfer from one partner to another, the magnetic resonance lines of colliding atoms are broadened and shifted in spin-exchange collisions. In particular the last two processes depend on the complex spin-exchange cross section. The real part of the cross section determines the so-called "spin-exchange cross section," which is responsible for the broadening of magnetic resonance lines, while the imaginary part determines the shift cross section, which governs the frequency shift of magnetic resonance. In order to describe the spin-exchange process one have to know complex spin-exchange cross sections. Complex spin-exchange cross sections are calculated on the basis of the data on the singlet (X 1 Σ + ) and triplet (a 3 Σ + ) potentials describing the interaction alkali-metal atoms in the ground state. Collisions of alkali-metal atoms Cs, Rb, K, Na in the ground state are considered in the energy interval of 10 −4 −10 −2 au.Collisions of alkali-metal atoms in the ground state with the electron spin S = 1/2 are accompanied by exchange of electron coordinates between colliding particles, which leads to polarization transfer between them (i.e., to the well-known phenomenon of spin exchange). In addition, along with the polarization transfer from one partner to another, the magnetic resonance lines of colliding atoms are broadened and shifted in spin-exchange collisions. In particular the last two processes depend on the complex spin-exchange cross section. The real part of the cross section determines the so-called "spin-exchange cross section," which is responsible for the broadening of magnetic resonance lines, while the imaginary part determines the shift cross section, which governs the frequency shift of magnetic resonance. In order to describe the spin-exchange process one have to know complex spin-exchange cross sections. Complex spin-exchange cross sections are calculated on the basis of the data on the singlet (X 1 Σ + ) and triplet (a 3 Σ + ) potentials describing the interaction alkali-metal atoms in the ground state. Collisions of alkali-metal atoms Cs, Rb, K, Na in the ground state are considered in the energy interval of 10 −4 −10 −2 au.

Journal of Physics Conference SeriesDec 1, 20180 citations

Multiply-excited atoms and line broadening

Petar Grujić

Journal of Applied SpectroscopySep 1, 19960 citations

The technique of Doppler-free two-photon spectroscopy was used to measure rates for line broadenings and frequency shifts of Rydberg levels with pressure. Measurements were made of spectra of

^{2}\mathrm{S}

and

^{2}\mathrm{D}

states (with n\ensuremath{\sim}10--40) for

{\mathrm{Rb}}^{\mathrm{*}\mathrm{*}}

+Rb and

{\mathrm{K}}^{\mathrm{*}\mathrm{*}}

+K, and of

^{2}\mathrm{S}

states (with n=14--29) for

{\mathrm{K}}^{\mathrm{*}\mathrm{*}}

+Rb. Large oscillations are observed in both broadening and shift rates for n\ensuremath{\sim}20--30 in all series except for the

^{2}\mathrm{D}

series in

{\mathrm{Rb}}^{\mathrm{*}\mathrm{*}}

+Rb. Overall rates for broadening and shift are compared with a theory based on the ``free-electron'' model. The observed oscillations are inconsistent with theories based on the resonance scattering of the Rydberg electron by the perturbing atom. A possible alternative mechanism related to interference in l-mixing collisions is suggested.