|Title||Anomalous broadening in driven dissipative Rydberg systems|
|Publication Type||Journal Article|
|Year of Publication||2016|
|Authors||Goldschmidt, EA, Boulier, T, Brown, RC, Koller, SB, Young, JT, Gorshkov, AV, Rolston, SL, Porto, JV|
|Journal||Physical Review Letters|
We observe interaction-induced broadening of the two-photon 5s-18s transition in 87Rb atoms trapped in a 3D optical lattice. The measured linewidth increases by nearly two orders of magnitude with increasing atomic density and excitation strength, with corresponding suppression of resonant scattering and enhancement of off-resonant scattering. We attribute the increased linewidth to resonant dipole-dipole interactions of 18s atoms with spontaneously created populations of nearby np states. Over a range of initial atomic densities and excitation strengths, the transition width is described by a single function of the steady-state density of Rydberg atoms, and the observed resonant excitation rate corresponds to that of a two-level system with the measured, rather than natural, linewidth. The broadening mechanism observed here is likely to have negative implications for many proposals with coherently interacting Rydberg atoms.