Ab initio study of permanent electric dipole moment and radiative lifetimes of alkaline-earth-metal--Li molecules

Journal Article · Thu Dec 15 00:00:00 EST 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.84.062514· OSTI ID:22095606

Gopakumar, Geetha; Abe, Minori; Hada, Masahiko ^[1]; Kajita, Masatoshi ^[2]

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1. Department of Chemistry, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan)
2. National Institute of Information and Communication Technology, Nukui-Kitamachi, Koganei, Tokyo 184-795 (Japan)

We calculate permanent electric dipole moments (PDMs), as well as spontaneous and black body lifetimes, of alkaline-earth-metal-Li (AEM-Li) ultracold polar molecules to study anisotropic long-range dipole-dipole interactions in a single quantum state. We obtain potential energy curves for the {sup 2} {Sigma} ground state of MgLi, CaLi, SrLi, and BaLi molecules at the coupled cluster singles and doubles with partial triples [CCSD(T)] level of electron correlation. Calculated spectroscopic constants for the isotopes: {sup 24}Mg{sup 7}Li, {sup 40}Ca{sup 7}Li, {sup 88}Sr{sup 7}Li, and {sup 138}Ba{sup 7}Li, show good agreement with available theoretical and experimental results. We obtain PDM curves using finite field perturbation theory at the CCSD(T) level. We find that AEM-Li molecules have moderate values of PDM at the equilibrium bond distance (MgLi: 0.90 D, CaLi: 1.15 D, SrLi: 0.33 D, and BaLi: -0.42 D) and hence might be suitable candidates for the proposed study in a single quantum state. Radiative lifetime calculations of the {nu} = 0 state ({sup 24}Mg{sup 6}Li: 22 s, {sup 40}Ca{sup 6}Li: 39 s, {sup 88}Sr{sup 6}Li: 380 s, and {sup 138}Ba{sup 6}Li: 988 s) are found to be longer than the typical time scale associated with ultracold experiments with these molecules. The uncertainty in the lifetime calculations are estimated to be less than 10%.

• OSTI ID: 22095606
• Journal Information: Physical Review. A, Vol. 84, Issue 6; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANISOTROPY
BARIUM
BARIUM 138
BOND LENGTHS
CALCIUM
CALCIUM 40
ELECTRIC DIPOLE MOMENTS
ELECTRON CORRELATION
GROUND STATES
INTERMETALLIC COMPOUNDS
LIFETIME
LITHIUM
LITHIUM 7
MAGNESIUM 24
MOLECULES
PERTURBATION THEORY
POTENTIAL ENERGY
QUANTUM STATES
STRONTIUM
STRONTIUM 88