External Field Control of Ultracold Atom-Molecule Mixtures: Magnetic Feshbach Resonances and Sympathetic Cooling of Polyatomic Molecules

超冷原子分子混合物的外场控制：费什巴赫磁共振和多原子分子的交感冷却

基本信息

批准号：
1912668
负责人：
Timur Tscherbul
金额：
$ 27万
依托单位：
Board of Regents, NSHE, obo University of Nevada, Reno
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：
2019-08-01 至 2022-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1912668&HistoricalAwards=false
关键词：
External Field Control Ultracold Atom

项目摘要

Quantum control of ultracold atoms, molecules, and ions with external electromagnetic fields is central to a wide variety of research fields. One widely-used control tool utilizes the sensitivity of long-lived quasi-stable (resonant) states between atoms. In particular, magnetic fields can be used to control so-called Feshbach resonances (MFRs) between atoms, a property that has been instrumental to the experimental realization of strongly correlated many-body states of matter for novel quantum materials. The prospect of controlling interactions of ultracold molecules is even more exciting, since these interactions are predicted to give rise to the highly exotic states of matter responsible for high-temperature superconductivity and novel topological phases. However, the tools for controlling molecular interactions with external magnetic fields are much less developed than those for atomic interactions, severely limiting the possibilities for controlling molecular many-body phenomena. The PI proposes to expand these possibilities by exploring MFRs in atom-molecule collisions using rigorous first-principle calculations. The study will pave the way toward precise quantum control of intermolecular interactions with applications to quantum simulation of condensed-matter systems, and to deep sympathetic cooling of trapped molecular gases.At present, numerically exact coupled-channel (CC) methodology cannot be used to study magnetic Feshbach resonances in ultracold atom-molecule collisions. This is due to the extreme computational difficulties caused by enormous CC basis sets, which must include all low-energy vibrational, rotational, and hyperfine molecular states coupled by strongly anisotropic intermolecular interactions. Particularly challenging to describe are the numerous hyperfine states, which arise due to the coupling between the electron and nuclear spins in the molecule, and play an important role in ultracold collisions. The PI proposes to address this issue by using flexible CC basis sets, which feature a variable number of hyperfine basis functions for different molecular rotational states. The use of the flexible basis states could reduce the computational complexity of CC calculations by several orders of magnitude, making it computationally feasible to calculate the spectrum of magnetic Feshbach resonances in ultracold atom-molecule mixtures of current experimental interest (such as Rb-SrF).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.

对具有外部电磁场的超低原子，分子和离子的量子控制对于各种研究领域都是核心。一种广泛使用的控制工具利用了原子之间长寿命的准稳定（共振）状态的灵敏度。特别是，磁场可用于控制原子之间所谓的feshbach共振（MFRS），该特性对新型量子材料的实验性实现具有强大相关的多体性状态的实验性具有重要意义。控制超低分子相互作用的前景更加令人兴奋，因为预计这些相互作用会引起高度外来的物质状态，导致高温超导性和新颖的拓扑阶段。但是，控制与外部磁场的分子相互作用的工具比原子相互作用的工具要少得多，这严重限制了控制分子多体现象的可能性。 PI建议通过使用严格的第一原则计算来探索原子分子碰撞中的MFR来扩展这些可能性。这项研究将为精确量子控制与量子间相互作用的精确量子控制铺平道路，并应用于对凝结物质系统的量子模拟以及对捕获的分子气体的深层交感神经冷却。在存在的情况下，在数值上精确的耦合通道（CC）方法论不能用于研究磁性Feshbach在超消极的磁性磁通量中超过胶质菌株。这是由于巨大的CC基集造成的极端计算困难，必须包括所有低能振动，旋转和超精细分子状态，并由强烈的各向异性分子间相互作用结合。描述特别具有挑战性的是众多的超细状态，这是由于分子中电子和核自旋之间的耦合而产生的，并且在超低碰撞中起着重要作用。 PI建议通过使用灵活的CC基集解决此问题，该集合具有不同的分子旋转状态的超精细基函数。柔性基础状态的使用可以减少几个数量级的计算复杂性，从而使其在计算上是可行的，以计算超低原子 - 原子 - 分子混合物中当前实验兴趣的磁性feshbach共振的频谱（例如，诸如RB-SRF之类的诸如RB-SRF）的范围。影响审查标准。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Spin coherence and optical properties of alkali-metal atoms in solid parahydrogen

DOI：
10.1103/physreva.100.063419
发表时间：
2019-10
期刊：
Physical Review A
影响因子：
2.9
作者：
S. Upadhyay;Ugne Dargyte;V. D. Dergachev;R. Prater;S. Varganov;T. Tscherbul;D. Patterson;J. Weinstein
通讯作者：
S. Upadhyay;Ugne Dargyte;V. D. Dergachev;R. Prater;S. Varganov;T. Tscherbul;D. Patterson;J. Weinstein

Near-threshold scaling of resonant inelastic collisions at ultralow temperatures