Rydberg Electrons as a Probe for Ultracold Systems

里德伯电子作为超冷系统的探针

• 批准号: 2034284
• 负责人: Robin Cote
• 金额: $ 24万
• 依托单位: University of Massachusetts Boston
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2034284&HistoricalAwards=false
• 关键词: Rydberg; Electrons; Probe; Ultracold; Systems

This project seeks to utilize Rydberg excitations, promotion of an electron in an atom to a very high energy level, to probe novel properties of ultracold gases. Rydberg atoms within an ultracold gas move very slowly, resulting in long collision times and large cumulative effects of even very weak interatomic forces. The large spatial extent of the Rydberg electron also renders the Rydberg atom sensitive to local field environments. The combination of these two factors, slow speed and large spatial volume, makes ultracold Rydberg atoms ideal probes of delicate correlations and other novel phenomena within the ultracold environment. During the past few years, experimental progress in preparing and manipulating ultracold Rydberg atoms has led to many new developments in Atomic, Molecular, and Optical (AMO) Physics. For example, Rydberg atoms have made possible the detection of a new class of long-range molecules, the so-called "trilobite"-like molecules, and of fast quantum gates relevant to the quantum information revolution. They are now utilized to make small regions of an otherwise opaque gas transparent, using what is known as electromagnetically induced transparency. Rydberg atoms can also generate single photon sources and mediate photon-photon interactions. Accordingly, ultracold Rydberg atom research bridges AMO, condensed matter and mesoscopic physics, and quantum information science, as well as ultracold chemistry. This theory project models the interactions of Rydberg electrons with their environment in order to better understand and predict observed spectra, which are expected to depend sensitively on the distribution of atoms in the gas, and enhance their utilization in the range of areas mentioned above. This research program explores how Rydberg electrons can be used to investigate few- and many-body phenomena. Rydberg electrons provide a low-energy and well-localized probe for AMO, condensed-matter, and chemical systems. While their wave function extends to large volumes, Rydberg electrons, being excited near the ionization threshold, have a small kinetic energy that minimally perturbs a system to be investigated. Rydberg electrons can scatter from one, two, or many ground-state atoms depending on the density of neighboring atoms. The effect of those scatterers on the Rydberg electron wave function can be used to study the properties of the ground-state atoms, such as their distribution and correlation, including in degenerate Bose or Fermi gases. In particular, the special case of two scatterers can shed light on Efimov physics, a three-body system with peculiar properties introduced in nuclear physics. To carry out this research, accurate wave functions are essential ingredients that current methods struggle to provide. Here, a non-perturbative approach based on Green's functions to compute wave functions and potential energy surfaces for Rydberg trilobite-like dimers, trimers, etc., will be developed. These accurate wave functions will then be employed in the calculation of photo-association (PA) spectra whose detailed lineshapes will unlock the information about the ground-state atoms, including their correlation (from two, three, four, or N-body). Finally, together with the computation of the Efimov wave functions, the probing of those elusive states with spectroscopic accuracy will be made possible.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目旨在利用里德伯激发，将原子中的电子提升到非常高的能级，来探测超冷气体的新特性。在超冷气体中的里德伯原子运动非常缓慢，导致了很长的碰撞时间和非常弱的原子间作用力的巨大累积效应。里德伯电子的大空间范围也使得里德伯原子对局域场环境敏感。速度慢和空间体积大这两个因素的结合，使超冷里德伯原子成为超冷环境中微妙关联和其他新现象的理想探针。在过去的几年中，制备和操纵超冷里德伯原子的实验进展导致了原子、分子和光学（AMO）物理学的许多新发展。例如，里德伯原子使检测一类新的远程分子成为可能，即所谓的“三叶虫”样分子，以及与量子信息革命相关的快速量子门。它们现在被用来使不透明气体的小区域变得透明，使用的是所谓的电磁感应透明。里德伯原子也可以产生单光子源和介导光子-光子相互作用。因此，超冷里德伯原子研究是AMO、凝聚态和介观物理、量子信息科学以及超冷化学的桥梁。该理论项目模拟了里德伯电子与其环境的相互作用，以便更好地理解和预测观测到的光谱，这些光谱预计将敏感地依赖于气体中原子的分布，并提高它们在上述区域范围内的利用。本研究计划探索如何利用里德伯电子来研究少体和多体现象。里德堡电子为AMO、凝聚态物质和化学系统提供了低能和定位良好的探针。当它们的波函数扩展到大体积时，里德堡电子，在电离阈值附近被激发，具有很小的动能，对待研究的系统的扰动最小。里德伯电子可以从一个、两个或许多基态原子散射，这取决于邻近原子的密度。这些散射体对里德伯电子波函数的影响可以用来研究基态原子的性质，比如它们的分布和相关性，包括在简并玻色或费米气体中。特别是，两个散射体的特殊情况可以阐明Efimov物理，这是核物理学中引入的具有特殊性质的三体系统。为了进行这项研究，精确的波函数是当前方法难以提供的基本成分。在这里，将开发一种基于Green函数的非摄动方法来计算Rydberg三叶虫样二聚体、三聚体等的波函数和势能面。这些精确的波函数将用于计算光关联（PA）光谱，其详细的线形将解开基态原子的信息，包括它们的相关性（来自二体、三体、四体或n体）。最后，结合叶菲莫夫波函数的计算，使以光谱精度探测这些难以捉摸的状态成为可能。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Phase-amplitude formalism for ultranarrow shape resonances

超窄形状共振的相位幅度形式主义

• DOI: 10.1103/physreva.99.022709
• 发表时间: 2019
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: Simbotin, I.;Shu, D.;Côté, R.
• 通讯作者: Côté, R.

Inner energy relaxation and growth of nanosize particles

• DOI: 10.1103/physreva.108.032812
• 发表时间: 2023-03
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: M. Bredice;M. Rozman;J. Smucker;E. Farmer;Robin Cot'e;V. Kharchenko

Model of charge transfer collisions between C 60 and slow ions

C 60 与慢离子之间的电荷转移碰撞模型

• DOI: 10.1063/5.0100357
• 发表时间: 2022
• 期刊: The Journal of Chemical Physics
• 作者: Smucker, J.;Montgomery, J. A.;Bredice, M.;Rozman, M. G.;Côté, R.;Sadeghpour, H. R.;Vrinceanu, D.;Kharchenko, V.
• 通讯作者: Kharchenko, V.

Homonuclear ion-atom collisions: Application to Li+−Li

同核离子原子碰撞：在 Li 上的应用

• DOI: 10.1103/physreva.105.063311
• 发表时间: 2022
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: Joshi, N.;Niranjan, M.;Pandey, A.;Dulieu, Olivier;Côté, Robin;Rangwala, S. A.
• 通讯作者: Rangwala, S. A.

Rydberg electron-atom scattering in forbidden regions of negative kinetic energy

负动能禁区内的里德伯电子原子散射

• DOI: 10.1088/1361-6455/ab7526
• 发表时间: 2020
• 期刊: Molecular and Optical Physics
• 作者: Stanojevic, Jovica;Côté, Robin
• 通讯作者: Côté, Robin