Competing Orders in Quantum Gases with Long-range Interactions

具有长程相互作用的量子气体中的竞争秩序

基本信息

批准号：
1707484
负责人：
Erhai Zhao
金额：
$ 22.5万
依托单位：
George Mason University
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=1707484&HistoricalAwards=false
关键词：
Competing Orders Quantum Gases Long

项目摘要

Recent experiments with trapped ensembles of magnetic atoms and/or polar molecules (molecules that have an electric dipole moment) have achieved the extremely cold temperatures at which quantum mechanical effects abound. Polar atoms and molecules attract and/or repel one another anisotropically (like a pair of magnets), and trapped collections of such particles are expected to display a variety of collective phenomena that are the focus of much current research. Modern experiments with dipolar gases are attempting to provide a controlled environment in which to synthesize, tune, and discover novel phases of polar quantum matter, complementary to the solid, liquid, gas and plasma phases familiar at higher temperatures. While polar systems are expected to display a wide variety of new phenomena, they are not yet well understood and their properties are challenging to predict theoretically. The difficulty arises from their sensitivity: Even small changes in density or temperature can change the phase of the ensemble, and so change observed properties dramatically. This project is developing new theoretical tools for the analysis of the plurality of phases of ultracold dipolar matter in order to improve our understanding of recent experimental observations. Graduate and undergraduate students will be trained through this project in scientific computing, data analysis and visualization in addition to physics. The project will develop two innovative many-body techniques for quantum gases with long-range interactions. The first is functional renormalization group for continuum Fermi gases at finite temperatures. It will be used to analyze the many-body instabilities and phase diagrams of dipolar Fermi gases in two-dimensions. The second is tensor network variational ansatz for dipolar atoms or molecules localized in deep optical lattices. It will be benchmarked and adapted to solve effective spin models with competing and long-range exchange interactions. The renormalization group technique will also be applied to study the many-body phases of other quantum gas systems including Rydberg dressed Fermi gases and spin-orbit coupled Fermi gases.

最近对磁性原子和/或极性分子（具有电偶极矩的分子）的捕获集合进行的实验已经实现了量子力学效应大量出现的极冷温度。极性原子和分子各向异性地相互吸引和/或排斥（就像一对磁铁），并且这些粒子的捕获集合预计会显示出各种集体现象，这是当前许多研究的焦点。现代偶极气体实验试图提供一个受控环境，在其中合成、调整和发现极性量子物质的新相，与高温下常见的固相、液相、气相和等离子体相互补。虽然极地系统预计会表现出各种各样的新现象，但它们尚未得到很好的理解，而且它们的特性很难从理论上预测。困难源于它们的敏感性：即使是密度或温度的微小变化也会改变系综的相位，从而显着改变观察到的特性。该项目正在开发新的理论工具来分析超冷偶极物质的多相，以提高我们对最近实验观测结果的理解。除了物理之外，研究生和本科生还将通过该项目接受科学计算、数据分析和可视化方面的培训。该项目将开发两种创新的多体技术，用于具有长程相互作用的量子气体。第一个是有限温度下连续费米气体的函数重正化群。它将用于分析二维偶极费米气体的多体不稳定性和相图。第二个是位于深层光学晶格中的偶极原子或分子的张量网络变分模拟。它将进行基准测试和调整，以解决具有竞争性和远程交换相互作用的有效自旋模型。重正化群技术还将应用于研究其他量子气体系统的多体相，包括里德堡修饰的费米气体和自旋轨道耦合费米气体。