An electric-field-assisted magnetic trap for cold molecular evaporative cooling: Toward molecular Bose–Einstein condensation.

Ultracold molecules provide fundamental new insights into molecular interaction dynamics in the quantum regime and represent a new platform for chemical physics where quantum behaviors play a dominant role in molecular interaction and dynamics. An electric-field-assisted magnetic trap for trapping and further evaporative cooling of cold molecules to ultracold regime is proposed utilizing the perturbation of the hyperfine levels in a mixed field, and the depth of the trap can be tuned by adjusting the assisted electric field rapidly. Thus, the evaporative cooling of 1 2 7 I 7 9 Br molecules in the | F = 4 , M F = − 4 〉 state of the rovibronic ground state is simulated. It shows that IBr molecules would be cooled from 26 μ K to 556 nK within 598.9 ms and eventually we would obtain a number of 4. 2 7 × 1 0 4 molecules in a volume of 3. 2 7 × 1 0 − 7 cm3 with the number density of 1. 3 0 × 1 0 1 2 cm − 3 . The Bose–Einstein condensation of the alkali diatomic molecules would probably be realized in the proposed trap if the present experimentally available samples are loaded. [ABSTRACT FROM AUTHOR]