Singlet-triplet anticrossings in 4He. III. Separation and mixing of the n=3-8 1D and 3D states

J. Derouard (1) , R. Jost (1) , M. Lombardi (1) , T. A. Miller (2) , R. S. Freund (2)

1 LSP - Laboratoire de Spectrométrie Physique
2 AT&T Bell Laboratories

The method of singlet-triplet anticrossing has been extended to the n1-3D levels of 4He with n=3, 4, and 5. We measure both the zero-field singlet-triplet separation with a higher accuracy than optical measurements, and the antisymmetric part of the spin-orbit coupling between singlet and triplet states. The agreement with many-body perturbation calculations for singlet-triplet intervals and with the hydrogenic approximation for spin-orbit coupling is fairly good even for low-n states. Values of singlet-triplet mixing in the n=3-8 D states, derived directly from the experimental results, are significantly more accurate than previous experimental and theoretical values.

Domaines: Physique Quantique [quant-ph]

J. Derouard, R. Jost, M. Lombardi, T. A. Miller, R. S. Freund. Singlet-triplet anticrossings in 4He. III. Separation and mixing of the n=3-8 1D and 3D states. Physical Review A, 1976, 14, pp.1025-1035. ⟨10.1103/PHYSREVA.14.1025⟩. ⟨hal-00974326⟩