Recently, there have been great interest and advancement in the field of laser cooling and magneto-optical trapping of molecules. The rich internal structure of molecules naturally lends themselves to extensive and exciting applications. In this paper, the radical^(138)Ba^(19) F, as a promising candidate for laser cooling and magneto-optical trapping, is discussed in detail.The highly diagonal Franck–Condon factors between the X^2Σ^+_(1/2)and A^2Π_(1/2) states are first confirmed with three different methods. Afterwards, with the effective Hamiltonian approach and irreducible tensor theory, the hyperfine structure of the X^2Σ^+_(1/2)state is calculated accurately. A scheme for laser cooling is given clearly. Besides, the Zeeman effects of the upper(A^2Π_(1/2)) and lower(X^2Σ^+_(1/2)) levels are also studied, and their respective g factors are obtained under a weak magnetic field.Its large g factor of the upper state A^2Π_(1/2) is advantageous for magneto-optical trapping. Finally, by studying Stark effect of Ba F in the X^2Σ^+_(1/2), we investigate the dependence of the internal effective electric field on the applied electric field. It is suggested that such a laser-cooled Ba F is also a promising candidate for precision measurement of electron electric dipole moment.
A scheme for storage of cold molecules in a hollow optical ring generated by a metasurface grating is proposed.The characteristics and intensity distribution related to the ring’s structural parameters and fabrication error tolerance are theoretically studied. The optical potential and dipole force required for the ring to trap magnesium monofluoride(MgF)molecules are also calculated. The dynamic behavior of MgF molecules in the storage ring is simulated by a Monte Carlo method, which shows that a metasurface-based optical storage ring can be used to trap molecules and is an interesting platform for research into ultracold quantum gases and their quantum-state manipulation.
