%0 Journal Article %J Phys. Rev. Lett. %D 2014 %T Beyond the spin model approximation for Ramsey spectroscopy %A A P Koller %A M Beverland %A Alexey V. Gorshkov %A A M Rey %B Phys. Rev. Lett. %V 112 %P 123001 %G eng %U http://link.aps.org/doi/10.1103/PhysRevLett.112.123001