Ultra-cold dipolar molecules have been identified as good candidates for quantum logic gates, tests of fundamental physics, and quantum simulations of more complex systems. To facilitate these applications, a method of generating high densities of dipolar molecules is critical. We have recently discovered a new excited resonance, a mixed state of the 4(1) and 2(1) long range potentials, which allows generation of cold molecules in the ground rovibronic state of the LiRb molecule by photoassociation followed by spontaneous decay. The estimated generation rate of these v=0 J=0 molecules is 4 x 10^3 molecules per second.
Laboratory measurements of the ground and excited potentials of this simple molecule are relatively recent. We have recently been exploring absorption resonances of the A 1S+ state and the D 3P state. These states will serve as important intermediate resonances as we work to vibrationally cool LiRb molecules produced in states other than v=0 J=0 by spontaneous decay. Our goal is to use coherent techniques to create rotational superposition states in vibrational ground state LiRb molecules and then preferentially photodissociate them.
S. Dutta, J. Lorenz, A. Altaf, D. S. Elliott, and Yong P. Chen, “Photoassociation of ultracold LiRb molecules: observation of high efficiency and rate saturation”, Phys. Rev. A 89, 020702(R) (2014)
S. Dutta, A. Altaf, J. Lorenz, D. S. Elliott and Yong P. Chen, “Interspecies collision-induced losses in a dual species 7Li-85Rb magneto-optical trap”, J. Phys. B: Atomic Molecular and Optical Physics 47, 105301 (2014)
J. Lorenz, A. Altaf, S. Dutta, Yong P. Chen, and D. S. Elliott, “Formation of deeply bound LiRb via Photoassociation near the Li 2S1/2 + Rb 5P3/2 asymptote”, Phys. Rev. A 89, 062513 (2014)
A. Altaf, S. Dutta, J. Lorenz, J. Perez-Rios, Yong P. Chen, and D. S. Elliott, “Formation of ultracold 7Li85Rb molecules in the lowest triplet electronic state by photoassociation and their detection by ionization spectroscopy”, J. Chem. Phys. 142, 114310 (2015)
I. C. Stevenson, D. Blasing, Y. P. Chen and D. S. Elliott, “Direct production of ultra-cold v=0 ground state LiRb molecules through photoassociation and spontaneous decay”, in preparation