Controllable dipolar energy transport with Rydberg dressed atoms

Ultracold Rydberg atoms exhibit strong and long-range state-changing interactions, and by optically coupling them to low-lying electronic states it is possible to create synthetic systems to investigate energy transfer dynamics and transport including controllable interactions and dissipation. We experimentally and theoretically study the dipole-mediated transport of Rydberg impurities through a surrounding gas of atoms coupled via an electromagnetically induced transparency (EIT) resonance. Interaction induced changes of the probe light absorption in the vicinity of each impurity allows us to monitor the spatial distribution of Rydberg excitations with high time and spatial resolution, and provides a controllable reservoir coupling. We present an effective spin-1/2 model for the impurity and dressed-atom system in which the ratio of the exchange interaction strength to the reservoir coupling strength determines the type of transport, including coherent exciton moti on, incoherent hopping, and a regime in which an emergent length scale leads to a preferred hopping distance far beyond nearest neighbours. For multiple impurities, the dissipation gives rise to strong nearest-neighbor correlations and entanglement, highlighting the importance of non-trivial dissipation, correlations and many-body effects in the dipole-mediated transport of Rydberg excitations