Cryogenic Neutral-Atom Arrays at Frontiers of Quantum Coherence

在不到一个世纪的时间里，量子物理学已经从一个有趣的谜题发展成为一个引人注目的现实，成为革命性计算思想的源泉。基于量子物理能力的计算机将能够以经典计算机无法比拟的速度解决某些任务，测量任务将受益于利用量子粒子之间相关性的能力。然而，物理学家和工程师在组装这些设备时面临着看似不可能完成的任务。完全隔离数千个单量子粒子，同时引入它们相互作用的方式是非常困难的。纠缠的脆弱性意味着其中一个粒子的扰动可能是灾难性的事件。这个项目的目标是设计一种技术，在由聚焦激光束制成的“镊子”中推进中性原子的隔离和控制，这是实现许多相互作用量子粒子的潜在新平台。通过在绝对零度以上4度的液态低温下操作，原子可以在陷阱中保持更长的时间，高度激发态，即里德伯态，可以有更长的寿命。这项工作将开发在低温环境中捕获原子的设备，并在小规模量子协议中展示相关的增强。这项工作将包括研究生培训和对本科教育的影响。单原子阵列的自下而上组装，它们的个体控制和纠缠机制，如里德堡激发，为量子计算提供了可扩展和可寻址的中性原子集的新视角。然而，由于量子相干性在多个方面的限制，进展可能很快就会饱和。本项目将开发一种基于闭式循环制冷机的新型低温装置，保持单原子控制，并在此基础上探索多个科学方向。作为最初的演示，研究人员将研究利用长存储时间捕获中性原子的非经典运动状态的创建，以及基准改进的里德伯寿命；最终，里德堡纠缠光学原子钟将受益于这项技术并与之结合。这项工作所代表的进步也将影响里德伯量子计算的发展，并为量子态合成和计量有用的量子态提供见解。此外，在量子飞跃的重大挑战中，量子科学的重要性和意义必须传播给下一代量子硬件研究人员和公众，该项目将纳入多种教育途径。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In less than a century, quantum physics has grown from an interesting puzzle, to a striking reality, to a source of revolutionary computational ideas. A computer based upon the power of quantum physics will be able to solve certain tasks at rates unmatched by classical computers, and measurement tasks will benefit from the ability to harness correlations between quantum particles. However, physicists and engineers face seemingly impossible tasks in assembling these devices. Fully isolating thousands of single quantum particles and at the same time introducing ways for them to interact is very difficult. The fragility of entanglement means that the disturbance of just one of those particles can be a catastrophic event. The goal of this project is to devise techniques to advance isolation and control of neutral atoms in "tweezers" made from focused laser beams, a potential new platform for realizing many interacting quantum particles. By operating at temperatures achieved with liquid cryogens, 4 degrees above absolute zero, the atoms can be held in traps for longer times, and highly-excited atomic states, known as Rydberg states, can have longer lifetimes. This work will develop devices that trap atoms held within a cryogenic environment, and demonstrate associated enhancements in small-scale quantum protocols. The work will encompass graduate student training and impact on undergraduate education.The bottom-up assembly of arrays of single atoms, their individual control, and entangling mechanism such as Rydberg excitation have enabled new perspectives on scalable and addressable sets of neutral atoms for quantum computing. However, advances could soon saturate due to limitations in multiple aspects of quantum coherence. This project will develop a new cryogenic apparatus based on a closed-cycle cryocooler that retains single-atom control, and subsequently explore multiple scientific directions. As initial demonstrations, the researchers will study the creation of non-classical states of motion of trapped neutral atoms harnessing long storage times, and benchmark improved Rydberg lifetimes; ultimately Rydberg-entangled optical atomic clocks will benefit from and combine with the technology. The advances represented by this work will also impact Rydberg quantum computing development, and provide insight into quantum state synthesis and metrologically-useful quantum states. Further, in the quantum leap grand challenge the import and meaning of quantum sciences must be propagated to a next generation of quantum-hardware researchers and to the general public, and the project will incorporate multiple avenues for education.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.