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团成长为惊人的现实，成为革命性计算思想的来源。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完成某些任务，而测量任务将受益于利用量子粒子之间的关联的能力。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法是非常困难的。纠缠的脆弱性意味着这些粒子中的一个粒子的扰动可能是灾难性的事件。该项目的目标是设计技术，以促进中性原子在聚焦激光制成的“镊子”中的隔离和控制，这是实现许多相互作用的量子粒子的潜在新平台。通过在液体制冷剂达到的温度下运行，原子可以在绝对零度以上4度的温度下被囚禁更长的时间，而且被称为里德堡态的高激发原子态可以有更长的寿命。这项工作将开发捕获保存在低温环境中的原子的设备，并展示小规模量子协议的相关增强。这项工作将包括研究生培养和对本科生教育的影响。单原子阵列的自下而上组装、它们的个人控制以及里德堡激发等纠缠机制使人们能够从新的角度研究用于量子计算的可扩展和可寻址的中性原子集。然而，由于量子相干的多个方面的限制，进展可能很快就会饱和。该项目将开发一种基于闭合循环制冷机的新低温设备，保持单原子控制，并随后探索多个科学方向。作为最初的演示，研究人员将研究利用长存储时间来创造囚禁中性原子的非经典运动状态，并对改善里德堡寿命的基准进行基准测试；最终，里德堡纠缠光学原子钟将受益于这项技术并与其相结合。这项工作所代表的进展也将影响里德伯格量子计算的发展，并为量子态合成和计量有用的量子态提供洞察。此外，在量子飞跃重大挑战中，量子科学的重要性和意义必须向下一代量子硬件研究人员和普通公众传播，该项目将纳入多种教育途径。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.