Calculations of Collisions Between Cold Alkaline-Earth-Metal Atoms in a Weak Laser Field

Published

September 1, 2001

Author(s)

M Machholm, Paul S. Julienne, K A. Suominem

Abstract

We calculate the light-induced collisional loss of laser-cooled and trapped magnesium atoms for detunings up to 50 atomic linewidths to the red of the ¹S_o-¹P₁ cooling transition. We evaluate loss rate coefficients due to both radiative and nonradiative state changing mechanisms for temperatures at and below the Doppler cooling temperature. We solve the Schrodinger equation with a complex potential to represent spontaneous decay, but also give analytic models for various limits. Vibrational structure due to molecular photoassociation is present in the trap loss spectrum. Relatively broad structure due to absorption to the Mg2 ¹ς_u state occurs for detunings larger than about 10 atomic line widths. Much sharper structure, especially evident at low temperature, occurs even at a smaller detunings due to of Mg₂¹ILg absorption, which is weakly allowed due to relativistic retardation corrections to the forbidden dipole transition strength. We also perform model studies for the other alkaline earth species Ca, Sr, and Ba and for Yb, and a find similar qualitative behavior as for Mg.

Citation

Physical Review A (Atomic, Molecular and Optical Physics)

Volume

64

Issue

No. 3

Pub Type

Journals

Keywords

alkaline earth atoms, barium, calcium, laser cooling, magnesium, photoassociation, strontium, trap loss collisions, ytterbium

Citation

Machholm, M. , Julienne, P. and Suominem, K. (2001), Calculations of Collisions Between Cold Alkaline-Earth-Metal Atoms in a Weak Laser Field, Physical Review A (Atomic, Molecular and Optical Physics) (Accessed April 26, 2024)