Two-dimensional atom-phonon coupling model for spin conversion: role of metastable states J. A. Nasser, S. Topçu, L. Chassagne, M. Wakim, B. Bennali, J. Linares and Y. Alayli Eur. Phys. J. B, 83 2 (2011) 115-132 Published online: 23 September 2011 DOI: 10.1140/epjb/e2011-10985-4