Photoassociation of cold heteronuclear dimers in static electric fields

The formation of heteronuclear molecules in their electronic ground states from a mixture of two ultracold atomic species via a one-photon stimulated emission process is investigated. The presence of an additional external homogeneous and static electric field is shown to severely influence the induced emission process. Using the LiCs molecule as a prototype, we study the corresponding cross section and its dependence on the continuum energy, final rovibrational state, and static electric field strength. The possibility of controlling the single-photon association process via an additional static electric field is demonstrated.

Figure 1

Electronic potential energy curve (a) and electric dipole moment function (b) of the electronic ground state of the LiCs molecule. Both quantities are given in atomic units. The schematics of the one-photon-induced emission process is shown in (a).

Figure 2

Cross sections for the induced emission process as a function of the vibrational label $30\le v\le 48$ of the final bound levels with angular momentum $J=0$ (a) and $1$ (b), for zero field strength and continuum energies corresponding to $E=1\mu \text{K}$ $(+)$, 10 K (◯), 0.1 mK (×), and 1 mK (◻).

Figure 3

Same as Fig. 2 but for $F={10}^{-5}\text{a.u.}$

Figure 4

Cross sections for the induced emission process as a function of the static electric field strength for the final states emerging from field-free levels with vibrational and rotational quantum numbers (40,0) (a) and (40,1) (b) for the continuum energies corresponding to $E=1\mu \text{K}$ (full line), $10\mu \text{K}$ (dashed line), 0.1 mK (dash-dotted line), and 1 mK (dotted line).

Figure 5

Contribution of the $p$ wave to the wave functions of the (40,0) (dashed) and (40,1) (solid) states as a function of the field strength.

Figure 6

Same as Fig. 4 but for the final states (47,0) and (47,1).