Effect of the diamagnetic interaction on the intensity of the radiation lines of an atom in a magnetic field

Asymptotic approximations to the energy of dispersion interaction between rubidium atoms in Rydberg states

“…the dipole-dipole interaction of the form C R 3 3 , which appears despite of absence of permanent electric-dipole moments in atoms. The situation is quite similar to a resonance for a frequency-dependent long-range susceptibility of ground-state atoms: the constant C 6 may be also enhanced by a laser radiation of a frequency corresponding to a two-atomic resonance on states of opposite parity [22], on analogy with the effect of the Förster-type resonance between opposite-parity Rydberg states npnp nsn f ñ -¢ ñ | | caused by the dipolequadrupole interaction, which was observed experimentally for ultracold Cs atoms [23].…”

“…Higher-order perturbation theory for the dispersion interaction of ground-state atoms was already considered in 1980s (see, for example [22,30,32] and references therein). Numerical data were calculated for coefficients determining asymptotic resolution of the third-order and fourth-order dispersion interaction energy for neutral hydrogen and alkali-metal atoms.…”

“…However, consecutive theoretical considerations of the external-field-induced Förster resonance with account of simultaneous actions of the field and the long-range interaction of Rydberg atoms, are still missing in the literature. The solution to this problem may be based on the use of the higher-order perturbation theory for the atom-field and atom-atom interactions on the straightforward analogy to the case of ground-state atoms in a field [22]. Corresponding susceptibilities of the two-atomic system would describe the energy shift dependence on the amplitude of external field, on the distance between atoms and on the relative orientation of the interatomic R and external field vectors.…”

“…The method used in this paper may be also applied to describing numerically the influence of static or oscillating electric field on the long-range interaction [22] between Rydberg atoms (see [43]). The data for evaluations of static polarizabilities and hyperpolarizabilities of Rydberg states in alkali atoms presented in [44] may be useful in this case.…”

The diamagnetic effect on the intensity of helium radiation lines

“…The first-order corrections to the matrix elements and intensities for the diamagnetic components of the Zeeman spectra were determined analytically and revealed some properties of the hydrogen-line intensity dependence on a magnetic field [13]. Analogous calculations for alkali atoms carried out within the model-potential (MP) method have discovered a significant dependence of the magneticfield-induced corrections to the radiation matrix elements both on the general structure of the energy levels and on the type of the radiation transition (σ or π ) [14]. A similar analysis for the magneticfield-dependent properties of the radiation transitions in helium will give essential information on the fundamental properties of atom-field interactions.…”