Coherent Excitation Transfer in a Spin Chain of Three Rydberg Atoms
  We study coherent excitation hopping in a spin chain realized using highly excited individually addressable Rydberg atoms. The dynamics are fully described in terms of an XY spin Hamiltonian with a long range resonant dipole-dipole coupling that scales as the inverse third power of the lattice spacing, $C_3/R^3$. The experimental data demonstrate the importance of next neighbor interactions which are manifest as revivals in the excitation dynamics. The results suggest that arrays of Rydberg atoms are ideally suited to large scale, high-fidelity quantum simulation of spin dynamics. 
Daniel Barredo, Henning Labuhn, Sylvain Ravets, Thierry Lahaye,   Antoine Browaeys and Charles S. Adams
quant-ph cond-mat.quant-gas physics.atom-ph