Laser Spectroscopy of Isolated Molecules and Complex Systems: Structure, Dynamics and Analysis

孤立分子和复杂系统的激光光谱：结构、动力学和分析

• 批准号: RGPIN-2019-04242
• 负责人: Grant, Edward
• 金额: $ 3.5万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=714004
• 关键词: Laser; Spectroscopy; Isolated; Molecules; Complex

Full-scale quantum computers will require large ensembles of qubits in protected states of sustained coherence. This presents a challenge. Isolated quantum systems of macroscopic size normally conform with the Eigenstate Thermalization Hypothesis. Here, quantum statistical mechanics applies, and eigenstate superpositions just evolve ergodically at a temperature defined by the energy density. But, in a development with great significance for the field of quantum materials, theory has found conditions under which disordered quantum many-body systems avoid decoherence, preserve spatial order and localize energy in superpositions of states. A small number of highly engineered experiments probing the dynamics of ultracold atoms confirm the principle of many-body localization (MBL) in optical lattices. In new research, we have changed the paradigm, offering a straightforward route to a state with all the hallmarks of MBL. We study Rydberg gases in which electron-impact avalanche ionization followed by shaped hydrodynamic expansion quenches the system to form an ultracold neutral plasma. Here, local integrals of motion (LIOM) govern the propagation of particle and energy density in a strongly disordered landscape. These LIOM create locally emergent conservation laws that guide the spontaneous formation of a global many-body localized state. Like lattice-based quantum many-body systems composed of ultracold atoms, the localized state of a quenched ultracold plasma offers promise as an analog quantum simulator, or a protected regime in which to embed discrete atomic or molecular qubits. New work will build on our preliminary observations of these quantum dynamics. We will further investigate the quenching and localization dynamics of nitric oxide and other ultracold plasmas. We will use a high-resolution digital synthesizer of mm-wave radiation to probe for localized (Poisson) versus delocalized (Wigner-Dyson) level-spacing statistics. The mechanics of avalanche and quench create a narrow distribution of particle distances. This may play a role in the quantum dynamics of arrested relaxation. We propose to study plasmas of NO and other molecules for the development of spatial correlation by means of coherent diffractive imaging with visible light. Interferometric imaging will also figure in a parallel program of Discovery Grant research on the sub-micron analysis and classification of complex materials by high-resolution interferometric backscattering (iSCAT) - Raman microscopy. We will develop multivariate analysis strategies that determine nanoparticle size distributions in real time, and probe three-dimensional structure in native samples. We illuminate a wide field by the acousto-optical deflection of a diffraction-limited focus. Frequency resolving this image affords a confocal Raman map as wide as 100 x 100 µm. We will build on these unique instrumental capabilities in a context of active local and international collaborations.

全尺寸量子计算机将需要大量处于持续相干保护状态的量子位。这是一个挑战。宏观尺度的孤立量子系统通常符合本征态热化假说。在这里，量子统计力学适用，本征态叠加只是在能量密度定义的温度下各态历经地演化。 但是，在对量子材料领域具有重大意义的发展中，理论已经发现了无序量子多体系统避免退相干、保持空间秩序和在叠加态中定位能量的条件。少数高度工程化的超冷原子动力学实验证实了光学晶格中的多体局域化（MBL）原理。 在新的研究中，我们改变了范式，提供了一条直接通往具有MBL所有特征的状态的途径。我们研究了里德伯气体，其中电子碰撞雪崩电离，然后通过形状的流体动力学膨胀淬灭系统，形成超冷中性等离子体。在这里，局部运动积分（LIOM）管理的传播粒子和能量密度在一个强烈的无序景观。这些LIOM创造了局部涌现的守恒定律，指导自发形成一个全球性的多体局域态。与由超冷原子组成的基于晶格的量子多体系统一样，淬火超冷等离子体的局域态提供了作为模拟量子模拟器的希望，或者是嵌入离散原子或分子量子比特的受保护机制。 新的工作将建立在我们对这些量子动力学的初步观察基础上。我们将进一步研究一氧化氮和其他超冷等离子体的淬灭和局部化动力学。我们将使用一个高分辨率的毫米波辐射数字合成器来探测局域（泊松）与非局域（维格纳-戴森）能级间距统计。雪崩和猝灭的机制产生了粒子距离的狭窄分布。 这可能在弛豫抑制的量子动力学中起作用。我们建议研究等离子体的NO和其他分子的空间相关性的发展，通过相干衍射成像与可见光。 干涉成像也将出现在一个并行计划的发现赠款研究的亚微米分析和分类的复杂材料的高分辨率干涉反向散射（iSCAT）-拉曼显微镜。 我们将开发多变量分析策略，以确定纳米颗粒的尺寸分布在真实的时间，并探测在本地样品的三维结构。我们通过衍射极限焦点的声光偏转来照明宽场。 对该图像进行频率分辨可得到宽达100 x 100 µm的共焦拉曼图。 我们将在积极的本地和国际合作的背景下建立这些独特的工具能力。