Photoassociative spectroscopy of ultracold metastable argon

M. K. Shaffer, Old Dominion University
G. Ranjit, Old Dominion University
C. I. Sukenik, Old Dominion University
M. Walhout, Calvin University


We present results of photoassociative spectroscopy performed on ultracold metastable argon atoms in a magneto-optical trap. Ion spectra are obtained with laser detuning up to a few gigahertz below the 4s[3/2]2→4p[5/2] 3 trapping transition at 811 nm and with intensities in a range of ∼(102-105)ISat. We also compute dipole-dipole potentials for both singly and doubly excited diatomic molecules and use a Leroy-Bernstein analysis to determine the approximate vibrational spacings in the (s+p) and (p+p) manifolds. Based on this theoretical framework, we explain a broad background feature in our data and suggest that double-excitation mechanisms are likely responsible for sharp dips in the ion signal. © 2011 American Physical Society.