Laser-controlled rotational cooling of Na-2 based on exceptional points
Abbreviated Journal Title
Phys. Rev. A
LONG-RANGE MOLECULES; GROUND-STATE; SCATTERING; DEGENERACIES; IONS; Optics; Physics, Atomic, Molecular & Chemical
Exceptional points (EPs) corresponding to resonance coalescence (i.e., complex energy degeneracy and identical wave functions) occur in many areas of non-Hermitian physics and, in particular, in laser-induced molecular dynamics for specific choices of two control parameters. We have previously shown [Atabek, et al., Phys. Rev. Lett. 106, 173002 (2011)] how these control parameters, namely, the wavelength and the intensity of the external field, have to be tuned to take advantage of EPs for selective vibrational transfers within a reduced one-dimensional model describing a diatomic molecule with frozen rotation. Moreover, the possibility offered by such transfers to adiabatically transport all the vibrational population to the ground v = 0 level has been presented as a realistic vibrational cooling strategy with an entropy flow toward the field-induced dissociative channel. The purpose of the present article is twofold: (i) Extend the model to a full three-dimensional quantum description of the rotating molecule and discuss the existence, determination, and role of EPs involving rovibrational resonances; (ii) examine the possibility for a further challenging step in obtaining ultracold molecules through combined vibrational and rotational laser control dynamics, aiming at total purification for reaching the ground (v = J = 0) rovibrational level. The illustrative example is the Na-2 molecule for which translationally cold species have experimentally been obtained.
Physical Review A
"Laser-controlled rotational cooling of Na-2 based on exceptional points" (2013). Faculty Bibliography 2010s. 4232.