Tunable optical potentials for ultra-cold atoms

光学技术可以精确控制超冷原子气体的内部和外部自由度。出于这个原因，超冷原子通常用于模拟其他物理系统，特别是那些通常具有实验挑战性或完全无法操纵的系统。该提议旨在为超冷原子气体创造可调谐的光学势。其基本目标是利用超冷气体的可调谐性来创建与其他物理系统（如天体物理和低温物理系统）的强大类比，并通过精确操纵超冷原子来进一步理解。 该提案的第一阶段将使用光学激发来研究有限温度下超冷量子气体中的磁化动力学。在这样的气体中，超流玻色-爱因斯坦凝聚体与非简并的正常气体组分共存。特别是，实验将试图了解自旋波激发的存在下，在未凝聚的组件如何影响系统的相干性，并将寻求研究这些气体中存在的不稳定性。这种丰富的物理系统既提供了与低温物理研究的重叠，又为精密计量应用提供了捕获气体系统的使用。 该提案的第二阶段扩展了可调谐光学势的创建，旨在使用光学技术在超冷气体中诱导原子之间的长程力。非共振激光器可以将原子置于超冷气体中，然后它们彼此相互作用。特殊的激光配置产生了与原子间距成反比的原子间势。这样的势能与引力势具有完全相同的数学形式，允许在实验室环境中探索人工可调的“电磁引力”。这项实验的目的是创造一个类似于冷玻色星星的物体，并用它来研究这种人造引力、动能和原子间的货车范德华力之间的相互作用。

Optical techniques allow precise control over the internal and external degrees of freedom in an ultra-cold gas of atoms. For this reason, ultra-cold atoms are often used to simulate other physical systems, especially ones that are typically experimentally challenging or completely inaccessible to manipulation. This proposal aims to create tunable optical potentials for ultra-cold atomic gases. The fundamental goal is to exploit the tunability of ultra-cold gases to create powerful analogies to other physical systems, such as astrophysical and low temperature physics systems, and to further understanding through precise manipulation of ultra-cold atoms. The first phase of this proposal will use optical excitations to study magnetization dynamics in an ultra-cold quantum gas at finite temperature. In such a gas, a superfluid Bose-Einstein condensate coexists with a non-degenerate normal gas component. In particular, the experiments will seek to understand how the presence of spin wave excitations in the uncondensed component affects the coherence of the system and will seek to study instabilities present in these gases. This rich physical system both provides overlap with low temperature physics research and informs the use of trapped gas systems for precision metrology applications. Extending the creation of tunable optical potentials, the second phase of the proposal seeks to induce long-range forces between atoms in an ultra-cold gas using optical techniques. Off-resonant lasers can polarize atoms in an ultra-cold gas, which then interact with each other. Special laser configurations create an interatomic potential that scales inversely with the atomic separation. Such a potential energy has the exact same mathematical form as a gravitational potential, allowing exploration of an artificial, tunable "electromagnetic gravity" in a laboratory setting. This experiment aims to create an analogue to a cold Bose star and use it to study the interplay between this artificial gravity, kinetic energy, and interatomic van der Waals forces.