Long-range interaction between polar Rydberg atoms

Flannery, M. R.; Vrînceanu, D.; Ostrovsky, V N

doi:10.1088/0953-4075/38/2/020

Cited by 43 publications

(42 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dominant term in the long-range electrostatic interaction series between two Rydberg atoms is the dipole-dipole interaction term [45]. This interaction is at the origin of diverse phenomena in cold Rydberg atom gases, such as resonant transitions of Rydberg-atom pairs [46,47], inelastic collisions [2], Penning ionization [48,49], Rydberg-excitation blockade [50][51][52] and the formation of Rydberg macrodimers [53][54][55].…”

Section: A Collision-induced Transitions Between Near-degenerate Levmentioning

confidence: 99%

Radiative and collisional processes in translationally cold samples of hydrogen Rydberg atoms studied in an electrostatic trap

Seiler¹,

Agner²,

Pillet³

et al. 2016

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

Supersonic beams of hydrogen atoms, prepared selectively in Rydberg-Stark states of principal quantum number n in the range between 25 and 35, have been deflected by 90 ○ , decelerated and loaded into off-axis electric traps at initial densities of ≈ 10 6 atoms/cm −3 and translational temperatures of 150 mK. The ability to confine the atoms spatially was exploited to study their decay by radiative and collisional processes. The evolution of the population of trapped atoms was measured for several milliseconds in dependence of the principal quantum number of the initially prepared states, the initial Rydberg-atom density in the trap, and the temperature of the environment of the trap, which could be varied between 7.5 K and 300 K using a cryorefrigerator. At room temperature, the population of trapped Rydberg atoms was found to decay faster than expected on the basis of their natural lifetimes, primarily because of absorption and emission stimulated by the thermal radiation field. At the lowest temperatures investigated experimentally, the decay was found to be multiexponential, with an initial rate scaling as n −4 and corresponding closely to the natural lifetimes of the initially prepared Rydberg-Stark states. The decay rate was found to continually decrease over time and to reach an almost n-independent rate of more than (1 ms) −1 after 3 ms. To analyze the experimentally observed decay of the populations of trapped atoms, numerical simulations were performed which included all radiative processes, i.e., spontaneous emission as well as absorption and emission stimulated by the thermal radiation. These simulations, however, systematically underestimated the population of trapped atoms observed after several milliseconds by almost two orders of magnitude, although they reliably predicted the decay rates of the remaining atoms in the trap. The calculations revealed that the atoms that remain in the trap for the longest times have larger absolute values of the magnetic quantum number m than the optically prepared RydbergStark states, and this observation led to the conclusion that a much more efficient mechanism than a purely radiative one must exist to induce transitions to Rydberg-Stark states of higher m values. While searching for such a mechanism, we discovered that resonant dipole-dipole collisions between Rydberg atoms in the trap represent an extremely efficient way of inducing transitions to states of higher m values. The efficiency of the mechanism is a consequence of the almost perfectly linear nature of the Stark effect at the moderate field strengths used to trap the atoms, which permits cascades of transitions between entire networks of near-degenerate Rydberg-atom-pair states. To include such cascades of resonant dipole-dipole transitions in the numerical simulations, we have generalized the two-state Förster-type collision model used to describe resonant collisions in ultracold Rydberg gases to a multi-state situation. It is only when considering the combined effects of collisional and radiative pr...

show abstract

Section: A Collision-induced Transitions Between Near-degenerate Levmentioning

confidence: 99%

Radiative and collisional processes in translationally cold samples of hydrogen Rydberg atoms studied in an electrostatic trap

Seiler¹,

Agner²,

Pillet³

et al. 2016

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

show abstract

“…Recently, there has been considerable interest in the study of helium dimers and ultracold helium collisions associated with metastable helium atoms [1,2,3,4,5,6,7,8,9,10,11].…”

mentioning

confidence: 99%

Long-range interactions between aHe(2S3)atom and a

et al. 2006

View full text Add to dashboard Cite

Long-range interactions between a He(2 3 S) atom and a He(2 3 P ) atom for like isotopes AbstractFor the interactions between a He(2 3 S) atom and a He(2 3 P ) atom for like isotopes, we report perturbation theoretic calculations using accurate variational wave functions in Hylleraas coordinates of the coefficients determining the potential energies at large internuclear separations. We evaluate the coefficient C 3 of the first order resonant dipole-dipole energy and the van der Waals coefficients C 6 , C 8 , and C 10 for the second order energies arising from the mutual perturbations of instantaneous electric dipole, quadrupole, and octupole interactions. We also evaluate the coefficient C 9 of the leading contribution to the third order energy. We establish definitive values including treatment of the finite nuclear mass for the 3 He(2 3 S)-3 He(2 3 P ) and 4 He(2 3 S)-4 He(2 3 P ) interactions.

show abstract

“…As long as the two atoms are well separated and their wave functions do not overlap, one needs to consider only the electrostatic interaction between two localized charge distributions, most conveniently utilizing the well-known electric multipole expansion in spherical coordinates [84][85][86]. The leading relevant term in this expansion is the dipole-dipole interaction [87] which, for unperturbed Rydberg atoms at large separation, results in the extensively studied van-der-Waals interaction [88][89][90][91]. More generally, as long as the interaction energies are small compared to the level spacing of the unperturbed Rydberg pair states, perturbative calculations offer a very convenient method for determining the radial [88] and angular [89,90] behavior of the Rydberg potentials.…”

Section: Rydberg Interactionmentioning

confidence: 99%

“…In the vicinity of a Förster resonance various angular momentum states mix and strongly anisotropic interaction can occur. Here, two single 87 Rb atoms were prepared in their ground state in two tightly focussed optical tweezers. Both the distance R between the two atoms and the angle θ between the interatomic axis and the external fields could be precisely tuned.…”

Section: Rydberg Interactionmentioning

confidence: 99%