Anisotropic interactions in an ultracold Dysprosium gas

我们对超导、超流体或量子磁性等宏观量子现象的从头开始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。强相互作用通常会导致强量子相关性，这有时会使理论模型变得难以处理，但例如，在存在拓扑秩序和鲁棒基态简并的情况下允许物质的新状态。在实验上，在单个粒子水平上的微观理解通常是不可接近的，只有平均或宏观数量/可观察到的东西被探测。用于超冷原子二维排列的量子气体显微镜已经引领了该领域的新范式，因为它们允许一个粒子一个粒子地检测空间结构，从而允许访问微观（量子）相关性。在这里，我们建议实现一个空间，能量和自旋分辨率的量子气体显微镜，用于最具磁性的原子镝，它允许费米子和玻色子系综，并证明了对长距离和短程相互作用的控制。为了最大限度地发挥由于偶极-偶极相互作用而产生的最近邻相互作用的效果，我们将在大约360 nm处使用近紫外晶格。与以前的实验相比，这种最近邻相互作用将被提高六倍。为了能够在紫外晶格上对单个原子成像，该显微镜将基于一种能量依赖的搁置技术，使用长寿命的电子状态以及最先进的磁场控制。使用搁置技术，所谓的“超分辨率”显微镜的极限可以达到，这提供了一个显着的改进阿贝极限。例如，在生物学中使用随机光学重建显微镜（STORM）或最近在冷原子中使用通过暗态进行原子定位。这种原子对原子的方法将被用来揭示各种宏观量子现象的微观本质：具有强近邻相互作用的物质的新相，例如二维中的霍尔丹链或条纹相，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是否存在短程相关性，但通过我们提出的实验工具，我们将能够将液滴冻结在UV晶格中，然后测量宏观相关性，从而挑战现有理论。微观分析将测试理论模型，并弥合新兴宏观量子现象与其潜在微观成分之间的差距

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