Engineering an all-optical route to ultracold molecules in their vibronic ground state

摘要

We propose an improved photoassociation scheme to produce ultracold moleculesin their vibronic ground state for the generic case where non-adiabatic effectsfacilitating transfer to deeply bound levels are absent. Formation of moleculesis achieved by short laser pulses in a Raman-like pump-dump process where anadditional near-infrared laser field couples the excited state to an auxiliarystate. The coupling due to the additional field effectively changes the shapeof the excited state potential and allows for efficient population transfer tolow-lying vibrational levels of the electronic ground state. Repetition of manypump-dump sequences together with collisional relaxation allows foraccumulation of molecules in v=0.