Interacting atoms in optical lattices

光学晶格中相互作用的原子

基本信息

批准号：
1707576
负责人：
David Weiss
金额：
$ 51万
依托单位：
Pennsylvania State Univ University Park
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2021-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1707576&HistoricalAwards=false
关键词：
Interacting atoms optical lattices

项目摘要

This project will study the quantum mechanical behavior of atoms in one dimensional (1D) gases. This is important because 1D gases are one of the few many-body systems for which exact quantitative predictions can be made about their quantum states. In comparison, most other quantum many-body systems are not "integrable," and therefore are much more challenging to describe. For this project, ultracold atoms will be prepared and then confined in 1D traps using laser light. The atomic momentum distributions in these 1D gases will be precisely measured under a variety of conditions, and this will serve as a benchmark test for advanced theoretical approaches that are being developed to understand many-body quantum systems. This project is also designed to observe quantum many-body phenomena such as "dynamical fermionization" and "prethermalization." These experiments will motivate new theoretical approaches that will also be relevant for nuclear and condensed matter physics, and will lead to a deeper understanding of quantum many-body phenomena such as superconductivity, magnetism, and quantum information processing. Students working on this project will learn advanced atomic physics research techniques that will prepare them for careers in academia or high tech industry.This team will work on three sets of measurements related to the momentum distributions of 1D Bose gases, using a technique that is dramatically more precise than previous approaches. The first set of measurements will be of equilibrium momentum distributions with intermediately and strongly coupled gases, for a range of temperatures. These will be compared to new theoretical calculations. Any disagreement would indicate that the 1D gases do not have a thermal distribution, despite their extremely gentle preparation starting from equilibrated 3D gases. The second set of measurements will entail the first observation of dynamical fermionization, where the initially bosonic momentum distribution of a Tonks-Girardeau gas transforms into that of a non-interacting Fermi gas, thus directly revealing the underlying conserved quantities in this system. The third set of measurements will measure the early stages of prethermalization after a quantum quench. The quench will be a Bragg scattering pulse, and the part of the ensuing evolution that is related to the point contact interactions is much faster than typical evolution in a trap. Comparisons with recently developed theory will be made. For the latter two sets of the measurements it is beyond existing theoretical methods to perform these dynamical calculations in the intermediate coupling regime. But the investigators propose to perform the experiments there as well, thus setting benchmarks for theorists to work toward.

该项目将研究原子在一维（1D）气体中的量子机械行为。这很重要，因为1D气体是可以对其量子状态进行精确定量预测的少数多体系统之一。相比之下，大多数其他量子多体系统不是“可集成的”，因此描述更具挑战性。对于此项目，将准备超速原子，然后使用激光光限制在1D陷阱中。这些1D气体中的原子动量分布将在各种条件下精确测量，这将作为正在开发的高级理论方法的基准测试，这些测试正在开发以了解多体量子系统。该项目还旨在观察量子多体现象，例如“动力费用”和“细头化”。这些实验将激发新的理论方法，这些方法也将与核和冷凝物理物理学相关，并会更深入地了解量子多体现象，例如超导性，磁性和量子信息处理。从事该项目的学生将学习先进的原子理研究技术，这些技术将为学术界或高科技行业的职业做好准备。该团队将使用比以前的方法更精确的技术进行三组与1D Bose气体动量分布相关的测量。对于一系列温度，第一组测量值将具有中间和强耦合气体的平衡动量分布。这些将与新的理论计算进行比较。任何分歧都表明，尽管1D气体从平衡的3D气体开始，但它们的制备非常温和，但1D气体没有热分布。第二组测量值将需要对动态费用的首次观察，其中最初的骨值动量分布将tonks-girardeau气体的气体分布转化为非相互作用的费米气体，因此直接揭示了该系统中的基本保守量。第三组测量值将测量量子淬火后的pr酸的早期阶段。淬灭将是一个bragg散射脉冲，随后的演化部分与点接触相互作用相关的速度要比陷阱中的典型进化快得多。将与最近开发的理论进行比较。对于后两组测量值，在中间耦合方案中执行这些动态计算超出了现有的理论方法。但是研究人员也建议在那里执行实验，从而为理论家努力努力。