Observation and Control of Coherent Processes Involving Rydberg Atoms

这个项目将研究单个原子对外部刺激的基本反应，例如其他原子的存在或非常短的明亮激光脉冲。这些实验将使用“里德堡原子”(其中至少有一个带负电荷的电子比正常情况下有更多的能量，并在带正电的原子核周围的大而慢的轨道上运动)。因为里德堡原子中原子核和远处电子之间的电场力非常弱，所以它们对周围的环境非常敏感。这种敏感性将在实验中被利用，放大原子对环境的反应，使其更容易以可控的方式改变电子的运动或操纵原子之间的力。其中一些实验可能会直接应用于量子计算，因为里德堡原子可能会用来存储和处理信息。在其他情况下，这些实验将为涉及更复杂系统的问题提供见解，例如光采集系统中的能量转移，或使用非常短的激光脉冲在极短的时间间隔内观察分子中的电子运动(所谓的“阿秒”区域，比1秒小100万倍)。实验将分别和结合利用超快和冷原子技术，利用强超短太赫兹脉冲和受控的原子间耦合来操纵电子动力学和/或原子-原子关联。这些系统有很多机会在超快/强场物理和冷原子物理之间的界面上探索少数体和多体量子力学的新方面。需要解决的问题是真正的挑战，因为与动力学有关的空间和时间尺度跨越许多数量级，从单个原子内的电子运动到涉及多个原子的关联。一组实验将寻求进一步描述暴露在强烈的、真正的单周期脉冲下的原子的新颖电离行为。另一种将尝试使用这种脉冲来诱导电离和复合，将束缚电子从原子连贯地穿梭到它们的邻近原子。第三行实验将利用激光有效地激发原子对以规定的原子间距离进出里德堡态，触发原子之间的强烈排斥相互作用，以操纵磁光囚禁中冷原子的位置关联。将探索在没有显式外部限制势的情况下产生原子的自序阵列的可能性。最后，原子之间的受控偶极-偶极耦合将被用来将电子波包纠缠到邻近原子上，从而导致相干电子波包运动从原子转移到它们的邻近原子，距离为几微米。从拟议的实验中获得的新见解可能会影响其他几个科学领域，包括凝聚态物理、化学物理、量子信息、量子控制和阿秒科学。

This project will study the fundamental response of individual atoms to external stimuli, such as the presence of other atoms or very brief pulses of bright laser light. The experiments will use "Rydberg atoms" (those in which at least one of the negatively-charged electrons has much more energy than normal and moves in a large, slow orbit around the positively-charged nucleus). Because the electric forces between the nucleus and the distant electron are so weak in Rydberg atoms, they are very sensitive to their surroundings. This sensitivity will be exploited in the experiments, magnifying the atom's response to its environment and making it easier to change the electron's motion or manipulate the forces between atoms in controlled ways. Some of the experiments could have direct applications in quantum computing because Rydberg atoms might serve to store and process information. In other cases, the experiments will provide insights to problems involving more complex systems, for example energy transfer in light harvesting systems, or the use of very brief laser pulses to view electron motion in molecules over extremely short time intervals (the so-called "attosecond" regime, which is a million-trillion times smaller than 1 second).The experiments will utilize ultrafast and cold atom techniques, separately and in combination, exploiting intense ultrashort terahertz pulses and controlled interatomic couplings to manipulate electron dynamics and/or atom-atom correlations. These systems are rich with opportunities for exploring novel aspects of few- and many-body quantum mechanics at the interface between ultrafast/strong field physics and cold atom physics. The problems to be addressed represent real challenges as the spatial and temporal scales relevant to the dynamics span many orders of magnitude, from electronic motion within individual atoms to correlations involving multiple atoms. One set of experiments will seek to further characterize the novel ionization behavior of atoms exposed to intense, true single-cycle pulses. Another will attempt to use such pulses to induce both ionization and recombination, coherently shuttling bound electrons from atoms to their neighbors. A third line of experiments will utilize efficient laser excitation of atom pairs into, and out of, Rydberg states at prescribed interatomic distances, toggling strong repulsive interactions between atoms to manipulate the position correlation of cold atoms in a magneto optical trap. Possibilities for producing self-ordered arrays of atoms without an explicit external confinement potential will be pursued. Lastly, controlled dipole-dipole couplings between atoms will be used to entangle electronic wavepackets on neighboring atoms, resulting in the transfer of coherent electronic wavepacket motion from atoms to their neighbors, at distances of several microns. New insights obtained from the proposed experiments have the potential to impact several other scientific areas including condensed matter physics, chemical physics, quantum information, quantum control, and attosecond science.