Anisotropic interactions in an ultracold Dysprosium gas

超冷镝气体中的各向异性相互作用

• 批准号: 287321116
• 负责人: Professor Dr. Tilman Pfau
• 金额: --
• 依托单位: 5. Physikalisches Institut
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/287321116?language=en
• 关键词: Anisotropic; interactions; ultracold; Dysprosium; gas

Our ab-initio understanding of macroscopic quantum phenomena like superconductivity, superfluidity or quantum magnetism relies on microscopic theoretical models which involve interacting constituents like electrons, holes, atoms or quasiparticles. Strong interactions often result in strong quantum correlations which sometimes render theoretical models intractable, but e.g. allow for new states of matter in the presence of topological order and robust ground state degeneracy. Experimentally, the microscopic understanding at the level of individual particles is often inaccessible, and only averaged or macroscopic quantities/observables are probed. Quantum gas microscopes for two-dimensional arrangements of ultracold atoms have led to a new paradigm in the field as they allow to detect spatial configurations particle by particle and therefore grant access to the microscopic (quantum-) correlations. Here we propose to implement a spatial-, energy- and spin-resolved quantum gas microscope for the most magnetic atom, Dysprosium, which allows for both fermionic and bosonic ensembles with proven control over long and short range interactions. To maximize the effect of the nearest-neighbour interaction due to the dipole-dipole interaction we will use a near UV lattice at around 360 nm. With this the nearest-neighbour interactions will be enhanced by a factor of six compared to previous experiments. To be able to image single atoms on the UV lattice, the microscope will be based on an energy-dependent shelving technique using a long-lived electronic state as well as a state-of-the-art magnetic field control. Using the shelving technique the so called "super-resolution" limit of microscopy can be reached, which provides a significant improvement over the Abbe limit. This it is done for example in biology using stochastic optical reconstruction microscopy (STORM) or more recently in cold atoms using atomic localisation through a dark state. This atom-by-atom-approach will be used to unravel the microscopic nature of various macroscopic quantum phenomena: new phases of matter with strong nearest-neighbour interactions, e.g. Haldane chain or stripe phase in 2D, and quantum magnetism in lattice spin models. It is not clear whether short-range correlations exist in the recently discovered quantum droplets, but with our proposed experimental tool we will be able to freeze the droplets in the UV lattice and then measure the macroscopic correlations and therefore challenge the existing theory. The microscopic analysis will test theoretical models and bridge the gap between emergent macroscopic quantum phenomena and their underlying microscopic ingredients

我们对超导、超流或量子磁性等宏观量子现象的从头算理解依赖于微观理论模型，这些模型涉及电子、空穴、原子或准粒子等相互作用的成分。强相互作用往往导致强量子关联，这有时使理论模型难以处理，但例如，允许在存在拓扑有序和健壮的基态简并的情况下出现新的物质状态。在实验上，在单个粒子水平上的微观理解通常是无法获得的，并且只探索平均或宏观的量/可观测值。超冷原子二维排列的量子气体显微镜在该领域带来了一种新的范式，因为它们允许逐个粒子地检测空间构型，从而允许进入微观(量子)关联。在这里，我们建议为最具磁性的原子Dy实现一个空间、能量和自旋分辨的量子气体显微镜，它允许费米子和玻色子的系综，并被证明可以控制长程和短程相互作用。为了最大化偶极-偶极相互作用引起的近邻相互作用的影响，我们将在360 nm左右使用近紫外晶格。有了这一点，与以前的实验相比，最近邻相互作用将增强到原来的六倍。为了能够在UV晶格上成像单个原子，该显微镜将基于一种依赖能量的搁置技术，使用长寿命电子态以及最先进的磁场控制。使用搁置技术可以达到显微镜的所谓“超分辨率”极限，这比阿贝极限有了很大的改进。例如，这是在生物学中使用随机光学重建显微镜(STORM)完成的，或者最近在冷原子中使用通过暗态的原子局域化完成的。这种逐个原子的方法将被用来揭开各种宏观量子现象的微观本质：具有强最近邻相互作用的物质的新相，例如2D中的Haldane链或条状相，以及晶格自旋模型中的量子磁性。目前尚不清楚最近发现的量子液滴中是否存在短程关联，但利用我们提出的实验工具，我们将能够冻结UV晶格中的液滴，然后测量宏观关联，从而挑战现有的理论。微观分析将检验理论模型，并弥合新兴宏观量子现象与其潜在微观成分之间的差距。