A Program in Ultralow-Temperature Atomic Physics

该计划的目标是在基础水平上学习材料。 其结果是对重要材料有了更深入的了解，并对材料特性的原理有了新的见解。 通过创建和研究新材料的模型，研究人员希望了解投机性新材料是否可以在自然界中实现。 该实验计划采用原子物理学中开发的方法，以前所未有的精度控制原子的运动和方向。 这些控制良好的积木现在可以组装成新材料，如乐高积木。 这些新材料可能表现出类似于尚未完全理解的天然材料的行为，甚至表现出以前从未见过的现象。 用分离良好的原子组装新形式的物质的优点是，构建模块及其相互作用是众所周知的，因此也是描述其行为的基本方程。 这共同导致了一个平台，在这个平台上，理论方法（分析这些方程）和实验方法（使用原子物理学的精度）可以结合起来，以获得对重要材料的更深入的理解，并找到合成新材料的新可能性。 该研究计划的主要重点是强磁场和磁耦合（称为自旋轨道耦合）如何改变半导体和金属中电子的性质。 由于我们的乐高积木是中性原子，因此真实的磁场被激光束帮助下产生的所谓合成磁场所取代。 此外，研究人员还将研究铁磁性的基本方面，并创造超冷分子。 实现新形式的超冷物质将促进我们对材料的理解，并为材料研究提供指导原则。 这项拟议的工作在其直接影响方面具有根本性意义，但从长远来看，它应该会产生具有未知特性的设备和先进材料，并开辟新的可能性和应用。 除了促进科学的进步，该项目还教育学生和博士后，并为他们在先进技术领域的职业生涯做好准备。更技术上，该项目的目标是进一步推进冷原子作为强关联物质模型系统的使用，同时通过创造自然界中没有已知对应物的材料将这种方法提升到一个新的水平。 本着量子模拟的精神，将准备代表物质理想化范式形式的多体哈密顿量的最简单可能实现的样本。未来五年的主要研究重点是合成规范场和自旋轨道耦合。 这些目标与当前多体理论和凝聚态物理学的前沿有着密切的联系，包括量子霍尔效应、拓扑绝缘体和强关联态。 这些材料比普通材料具有更深刻的量子力学性质，因为它们利用了非平凡的量子力学相位（几何相位，Berry相位）或量子纠缠。 此外，计划探索巡回铁磁性，使用绝热状态制备冷却到皮开尔文温度，以及钠锂二聚体作为异质偶极分子。

The goal of this program is to study materials at a fundamental level. The result is a deeper understanding of important materials, and new insights into the principles of material properties. By creating and studying models of new materials, the researchers want to find out if speculative new materials can be realized in Nature. The experimental program employs methods developed in atomic physics to control the motion and orientation of atoms with unprecedented precision. Those well controlled building blocks can now be assembled into new materials like Lego pieces. These new materials may show behavior similar to naturally occurring materials which are not fully understood, or even display phenomena never seen before. Assembling new forms of matter with well separated atoms has the advantage that the building blocks and their interactions are well known, and therefore also the basic equations describing their behavior. This together leads to a platform where both theoretical methods (analyzing these equations) and experimental methods (using the precision of atomic physics) can be combined to obtain a deeper understanding for important materials and find new possibilities for synthesizing new materials. The major focus of the research program is on the question how strong magnetic fields and magnetic couplings (called spin-orbit coupling) change the properties of electrons in semiconductors and metals. Since our Lego pieces are neutral atoms, real magnetic fields are replaced by so-called synthetic magnetic fields created with the help of laser beams. In addition, the researchers will study fundamental aspects of ferromagnetism, and create ultracold molecules. The realization of new forms of ultracold matter will advance our understanding of materials and provide guiding principles for materials research. The proposed work is fundamental in its immediate impact, but in the long run, it should lead to devices and advanced materials with yet unknown properties, and open new possibilities and applications. Besides promoting the progress of science; this program educates students and postdocs and prepares them for a career in areas of advanced technology.More technically, the goal of this project is to further advance the use of cold atoms as model systems for strongly correlated matter, but also to take this approach to the next level by creating materials with no known counterpart in Nature. In the spirit of quantum simulations, samples will be prepared which are the simplest possible realizations of many-body Hamiltonians representing idealized paradigmatic forms of matter. The major foci of the proposed research in the next five years are the themes of synthetic gauge fields and spin orbit coupling. These goals make strong connections with current frontiers in many-body theory and in condensed matter physics, including the quantum Hall effect, topological insulators, and strongly correlated states. These materials are more profoundly quantum mechanical than ordinary materials because they exploit non-trivial quantum mechanical phases (geometric phases, Berry phase) or quantum entanglement. In addition,it is planned to explore itinerant ferromagnetism, cooling to picokelvin temperatures using adiabatic state preparation, and the sodium-lithium dimer as a heteronuclear dipolar molecule.