Quantum State Engineering with Bose-Einstein Condensates: Dressed-State and Hydrodynamic Approaches

该项目采用超冷原子气体来模拟复杂的量子力学现象。使用激光冷却和相关技术，原子云被冷却到接近绝对零度的温度。在适当的条件下，原子聚结成玻色-爱因斯坦凝聚体，这是一种表现出量子力学行为的宏观物质波。这些物体的尺寸很大，可以延伸到数百微米，这意味着它们很容易使用自定义成像光学器件进行观察，并且基于原子物理学的丰富工具集可用于它们的操作。这一点，再加上它们的量子力学性质，使它们成为研究复杂量子力学现象的理想平台。随着新的实验工具和理论方法的不断发展，这种量子模拟建模已经成为原子、分子和光学（AMO）物理学研究的一个主要方向。超冷原子平台可用于研究凝聚态物理、非线性科学、流体力学、量子光学等现象，证明了它们作为现代物理学中高度通用的试验平台的重要性。在这个项目中进行的实验研究了几种方法来探测从玻色-爱因斯坦凝聚体的宏观物质波中出现的具有晶体性质的周期性结构。这种晶体结构的动力学性质提出了许多理论挑战，实验为理论理解的发展提供了重要的基准数据。超越超冷原子的领域，通过这一研究路线获得的洞察力对凝聚态物理和非线性科学也具有高度相关性。实验采用复杂的设置进行，这些设置利用了大量的现代实验技术，包括激光和光学，真空技术，自动化编程和先进的电子技术。这使得它们成为理想的平台，可以在与现代量子技术相关的众多领域培训学生，这些技术在传感器应用中使用量子力学效应，例如检测磁场，电场或引力场，从根本上安全通信，或建立新的高效计算范例。 该研究计划主张使用超冷原子气体作为研究量子相位和动力学的高度灵活的平台。沿着量子模拟的思路，采用了几种创新的方法来研究稀气体玻色-爱因斯坦凝聚体（BEC）中出现的能带结构和相关现象。出发点是一个BEC中的自旋和运动的自由度耦合的一组拉曼激光束。这种自旋-轨道耦合然后用射频敷料或微波敷料补充，以产生具有不寻常特性的有效晶格结构。在第一种情况下，一个有效的塞曼晶格出现，即使没有自旋轨道耦合，也没有射频单独产生周期性的能带结构。第二种情况导致了一种新的方法来产生一个超固态的状态与大的空间周期性，克服了以前的方法的局限性。作为第三种补充方法，从量子流体力学的角度来看，密集包装的相互作用孤子列车的实验实现提供了一个非常不同的和未经探索的访问超流体系统中出现的晶体性质的研究，而不施加周期性的外部电位。 使用原子物理学的通用工具箱对凝聚态、流体动力学或非线性现象进行量子模拟是量子气体研究中的一个高度活跃的领域，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查进行评估来支持的搜索.

This project employs ultracold atomic gases to model complex quantum mechanical phenomena. Using laser cooling and related techniques, a cloud of atoms is cooled down to temperatures near absolute zero. Under appropriate conditions the atoms coalesce into a Bose-Einstein condensate, a macroscopic matter wave displaying quantum mechanical behavior. The large size of these objects, which can extend over hundreds of microns, implies that they are readily observable using custom imaging optics, and a rich toolset based on atomic physics is available for their manipulation. This, together with their quantum mechanical nature, makes them an ideal platform to study complex quantum mechanical phenomena. With the recent and ongoing development of novel experimental tools and theoretical approaches, such quantum analog modeling has become a major thrust of research in Atomic, Molecular and Optical (AMO) physics. Ultracold atom platforms can be applied to study phenomena from condensed matter physics, nonlinear science, hydrodynamics, quantum optics, and more, demonstrating their importance as highly versatile testbeds in modern physics. The experiments conducted in this project investigate several approaches to probe the emergence of periodic structures with crystal-like properties from the macroscopic matter wave of a Bose-Einstein condensate. The dynamical properties of such crystalline structures pose many theoretical challenges, and the experiments provide essential benchmark data for the development of a theoretical understanding. Going beyond the realm of ultracold atoms, the insight gained through this line of research is of high relevance for condensed matter physics and nonlinear science as well. The experiments are conducted with complex setups that utilize a large range of modern experimental techniques, including lasers and optics, ultrahigh vacuum technology, automation programming, and advanced electronics. This makes them ideal platforms to train students in a multitude of areas relevant for modern quantum technologies which use quantum mechanical effects in sensor applications e.g. to detect magnetic, electric or gravitational fields, for fundamentally secure communication, or to establish new paradigms for efficient computing. This research program advocates the use of ultracold atomic gases as a highly flexible platform for the study of quantum phases and dynamics. Along the lines of quantum analog simulation, several innovative approaches to investigate emerging band structures and associated phenomena in dilute-gas Bose-Einstein condensates (BECs) are employed. The starting point is a BEC in which spin and motional degrees of freedom are coupled by a set of Raman laser beams. This spin-orbit coupling is then supplemented with a radiofrequency dressing or microwave dressing to generate effective lattice structures with unusual properties. In the first case, an effective Zeeman lattice emerges even though neither the spin-orbit coupling nor the radiofrequency alone produce a periodic band structure. The second case leads to a new method to generate a supersolid-like state with large spatial periodicity, overcoming the limitations of previous approaches. As a third, complementary approach coming from a quantum hydrodynamics perspective, the experimental realization of densely packed interacting soliton trains provides a very different and unexplored access to the study of crystalline properties that arise in a superfluid system without imposing a periodic external potential. The quantum analog simulation of condensed matter, hydrodynamic or nonlinear phenomena using the versatile toolbox of atomic physics is a highly active area in quantum gas research, and the experiments provide important benchmark data motivating the concurrent development of theoretical approaches.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.