Quantum Gases of Bosonic and Fermionic Lithium

玻色子和费米子锂的量子气体

基本信息

批准号：
1707992
负责人：
Randall Hulet
金额：
$ 58.93万
依托单位：
William Marsh Rice University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1707992&HistoricalAwards=false
关键词：
Quantum Gases Bosonic Fermionic Lithium

项目摘要

For electrons in solids it is well known that quantum many-body interactions cause material properties such as conductivity and magnetism. For atoms in a gas, however, it is difficult to observe quantum many-body effects unless the atoms are very cold, because hot atoms behave more like ordinary ballistic particles. This project will cool lithium atoms below one millionth of a degree Kelvin and manipulate gases of ultra-cold atoms in optical traps in order to study how quantum mechanics influences large collections of atoms. This will advance the science known as quantum many-body physics. The advantage of using ultra-cold atoms is that their temperature, density, and traps can be readily controlled and adjusted. This is important because it will help physicists understand phenomena such as superconductivity and exotic types of magnetism. In particular, this project will study how magnetism and superconductivity co-exist. This will improve the fundamental understanding of high-temperature superconductors, and may enable fabrication of new materials that superconduct at even higher temperatures. Another part of this project will probe how quantum many-body phenomena affect the propagation of collective waves known as solitons. This part of the project is important because it could lead to improved sensors.Both parts of this project will use an isotope of lithium, in one case a boson, while in the other a fermion. The goal of the proposed boson experiment is to explore the role of near-integrability in bright matter-wave solitons, either fundamental ones or higher-order soliton breathers. The plan is to create a breather using a protocol developed by theoretical collaborators, and to explore its interactions with a beam splitter formed from a blue-detuned light sheet. The goals are both fundamental and technological. One goal is to create a mesoscopic (N = 100-300) quantum object and observe its properties in a novel one-dimensional interferometer using the light sheet as a beam splitter. If the center-of-mass energy of the soliton is below the binding energy of a single atom, it will not fragment upon interacting with the beam splitter, but rather tunnel and reflect in its entirety, thus creating a Schrödinger cat state. In the second part of this project, this laboratory will implement new ideas for creating and directly detecting the exotic superconducting state known as FFLO (Fulde-Ferrell-Larkin-Ovchinnikov state) with a spin-imbalanced Fermi gas. While FFLO is prevalent in 1D, both quantum and thermal fluctuations tend to destroy long-range order in lower dimensions. The recent determination from this laboratory of the phase diagram of the 1D-3D dimensional crossover in a gas of spin-polarized fermions points to a region in parameter space where FFLO is both prevalent and stable. The next goal for this team is to detect the periodic domain walls occupied by the unpaired fermions in time-of-flight expansion in 1D. This would constitute the first direct evidence for FFLO.

对于固体中的电子，众所周知，量子多体相互作用会导致材料特性，例如电导率和磁性，然而，对于气体中的原子，除非原子非常冷，否则很难观察到量子多体效应，因为原子很热。原子的行为更像普通的弹道粒子，该项目将把锂原子冷却到百万分之一开尔文度以下，并操纵光陷阱中的超冷原子气体，以研究量子力学如何影响大量原子，这将推动科学发展。被称为量子使用超冷原子的优点是可以轻松控制和调整它们的温度、密度和陷阱，这很重要，因为它将帮助物理学家理解超导和奇异类型的磁性等现象。该项目将研究磁性和超导性如何共存，这将提高对高温超导体的基本理解，并可能实现在更高温度下超导的新材料的制造。该项目的另一部分将进行探索。量子多体现象如何影响被称为孤子的集体波的传播，该项目的这一部分很重要，因为它可以改进传感器。该项目的两个部分都将使用锂同位素，在一种情况下是玻色子，而所提出的玻色子实验的目标是探索亮物质波孤子（无论是基本孤子还是高阶孤子呼吸器）中的近可积性的作用。呼吸器使用理论合作者开发的协议，并探索其与由蓝色失谐光片形成的分束器的相互作用，其中一个目标是创建介观（N = 100-300）量子。物体并在使用光片作为分束器的新型一维干涉仪中观察其特性如果孤子的质心能量低于单个原子的结合能，则它在与原子相互作用时不会碎裂。在该项目的第二部分中，该实验室将实施新的想法来创建和直接检测称为 FFLO（富尔德-费雷尔）的奇异超导状态。 -Larkin-Ovchinnikov 态），具有自旋不平衡费米气体，虽然 FFLO 在 1D 中普遍存在，但量子和热涨落往往会破坏较低维度的长程有序。该实验室最近确定的自旋极化费米子气体中 1D-3D 维度交叉的相图指出了参数空间中 FFLO 既普遍又稳定的区域。该团队的下一个目标是检测周期性。一维飞行时间扩展中不成对的费米子占据的磁畴壁这将构成 FFLO 的第一个直接证据。

项目成果

期刊论文数量（14）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Emergence and Disruption of Spin-Charge Separation in One-Dimensional Repulsive Fermions

一维排斥费米子中自旋电荷分离的出现和破坏

DOI：
10.1103/physrevlett.125.190401
发表时间：
2020-11
期刊：
Physical Review Letters
影响因子：
8.6
作者：
He, Feng;Jiang, Yu;Lin, Hai;Hulet, Randall G.;Pu, Han;Guan, Xi
通讯作者：
Guan, Xi

Methods for preparing quantum gases of lithium

锂量子气体的制备方法

DOI：
10.1063/1.5131023
发表时间：
2020-01
期刊：
Review of Scientific Instruments
影响因子：
1.6
作者：
Hulet, Randall G.;Nguyen, Jason H. V.;Senaratne, Ruwan
通讯作者：
Senaratne, Ruwan

Quantum Fluctuations of the Center of Mass and Relative Parameters of Nonlinear Schrödinger Breathers

非线性薛定谔呼吸器质心的量子涨落及相关参数

DOI：
10.1103/physrevlett.125.050405
发表时间：
2020-07
期刊：
Physical Review Letters
影响因子：
8.6
作者：
Marchukov, Oleksandr V.;Malomed, Boris A.;Dunjko, Vanja;Ruhl, Joanna;Olshanii, Maxim;Hulet, Randall G.;Yurovsky, Vladimir A.
通讯作者：
Yurovsky, Vladimir A.

Measurement of the Dynamical Structure Factor of a 1D Interacting Fermi Gas

一维相互作用费米气体的动态结构因子的测量

DOI：
10.1103/physrevlett.121.103001
发表时间：
2018-09
期刊：
Physical Review Letters
影响因子：
8.6
作者：
Yang, T. L.;Grišins, P.;Chang, Y. T.;Zhao, Z. H.;Shih, C. Y.;Giamarchi, T.;Hulet, R. G.
通讯作者：
Hulet, R. G.

Dissociation of One-Dimensional Matter-Wave Breathers due to Quantum Many-Body Effects

量子多体效应导致的一维物质波呼吸体的解离