Long-range interactions of metastable helium atoms

Abstract

Polarizabilities, dispersion coefficients, and long-range atom-surface interaction potentials are calculated for the n = 2 triplet and singlet states of helium using highly accurate, variationally determined, wave functions.

Theory of evaporative cooling with energy-dependent elastic scattering cross section and application to metastable helium

“…From the Stärck and Meyer potential [8] a scattering length a = +8.3 nm is deduced. More recently, Gadéa, Leininger and Dickinson [10] calculated the short-range part of this potential more accurately and combining their potential with the accurately determined long-range potential of Yan and Babb [19] they determine a = +15.4 nm. However, the value of the scattering length is very sensitive to the way the short-range and long-range potential are connected.…”

Feshbach resonances inHe3*-Goosen1, Tiecke2, Vassen3 et al. 2010Phys. Rev. A142320View full textAdd to dashboardCite

“…We construct the full S = 2 potential by fitting the shortrange potential by Przybytek [4] to the long-range dispersive potential V disp (r) = −C 6 /r 6 − C 8 /r 8 − C 10 /r 10 using the accurately known dispersive coefficients [30]. We forge these potentials around r = 20a 0 by vertically shifting the short-range potential to match the long-range potential and by applying a smoothing function.…”

Tensorial analysis of the long-range interaction between metastable alkaline-earth-metal atoms

“…(10). By putting to use the celebrated Wigner-Eckart theorem [48], the matrix elements of the operator M 2,0 , for instance, can be written as…”

“…Dispersion coefficients for metastable helium, 2 1 S 0 and 2 3 S 1 , have been calculated, for example, by Chen [9] and by Yan and Babb [10]. The metastable states of the heavier noble gases can be written as np 5 (n + 1)s 3 P 2 (n = 2 for neon, and so on).…”