Rydberg Atom Interactions and Collective Behavior

里德伯原子极大的极化率导致了原子核间距离为微米的相互作用，这比它们在超冷温度（T小于1毫开尔文）下的动能要大。超冷里德伯原子的长程相互作用使其成为研究偶极量子气体、建立单光子源和构造量子门的重要体系。它们对电场的敏感性使得里德伯原子在传感和测量标准方面的应用非常有用。利用里德堡原子偶极阻断产生量子纠缠物质粒子、增加光物质相互作用时间和创造奇异态（如大二聚体和三叶虫分子）的能力进一步激发了对超冷里德堡原子的研究。我们正在解决的关键问题是：如何控制相互作用的各向异性，静态背景电场的作用是什么，超冷气体中的里德伯原子-电子散射如何导致有趣的物质状态的形成，以及当两个里德伯原子在短距离相互作用时会发生什么？具体地说，超冷基态原子和里德伯原子电子之间的相互作用正在实验研究与独特的碰撞成像光谱仪。相变和磁现象，预计将发生由于弱束缚的里德伯电子从基态原子的散射正在研究。这些实验补充了里德堡原子-里德堡原子相互作用的其他实验，这些实验定量测量了相互作用的各向异性及其对相变的影响，这些相变被假设发生在超冷里德堡气体中。这些实验的结果正在与我们研究小组的理论进行比较。该奖项支持两名研究生，并使本科生的研究项目进行的设备。

The extremely large polarizability of Rydberg atoms leads to interactions at internuclear distances of microns that are larger than their kinetic energies at ultracold temperatures (T less than 1 milliKelvin). The long range interactions make ultracold Rydberg atoms important systems for studying dipolar quantum gases, building single photon sources and constructing quantum gates. Their sensitivity to electric fields makes Rydberg atoms useful for applications in sensing and measurement standards. The ability to generate quantum entangled material particles using Rydberg atom dipole blockade, increase light matter interaction times, and create exotic states, like macrodimers and trilobite molecules, has further motivated the study of ultracold Rydberg atoms. Key questions that we are addressing are: how can the anisotropy of the interactions be controlled, what is the role of static background electric fields, how does Rydberg atom-electron scattering in ultracold gases lead to the formation of interesting states of matter and what happens when two Rydberg atoms interact at short range? Specifically, the interaction between ultracold ground state atoms and Rydberg atom electrons is being investigated experimentally with a unique collision imaging spectrometer. Phase transitions and magnetic phenomena that are predicted to occur due to the scattering of the weakly bound Rydberg electron from the ground state atoms are being studied. These experiments complement others on Rydberg atom- Rydberg atom interactions, which quantitatively measure the anisotropy of the interactions and their influence on phase transitions that are postulated to occur in ultracold Rydberg gases. The results of these experiments are being compared to theory done by our research group. This award supports two graduate students and enables undergraduate research projects to be carried out on the apparatus.