We study the long-range interaction of a single ion with a highly excited ultracold Rydberg atom and report on the direct observation of an ion-induced Rydberg excitation blockade mediated over tens of micrometer distances. Our hybrid ion-atom system is directly produced from an ultracold atomic ensemble via near-threshold photoionization of a single Rydberg excitation, employing a two-photon scheme that is specifically suited for generating a very low-energy ion. The ion’s motion is precisely controlled by small electric fields, which allows us to analyze the blockade mechanism for a range of principal quantum numbers. Finally, we explore the capability of the ion as a high-sensitivity, single-atom-based electric field sensor. The observed ion-Rydberg-atom interaction is of current interest for entanglement generation or studies of ultracold chemistry in hybrid ion-atom systems.

我们研究了单个离子与高度激发的超冷Rydberg原子的远程相互作用，并报道了在数十微米距离内介导的离子诱导的Rydberg激发阻滞的直接观察。我们的混合离子-原子系统是由超冷原子团直接通过单个里德堡激发的近阈光电离而产生的，采用了特别适合于产生非常低能量离子的双光子方案。离子的运动由小电场精确控制，这使我们能够分析一系列主要量子数的阻滞机理。最后，我们探索了离子作为高灵敏度，基于单原子的电场传感器的功能。