Cryogenic Neutral Atom Arrays for Quantum Processors

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惊人的现实，成为革命性计算思想的源泉。 基于量子物理学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的相关性的能力。 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其中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，以推进由聚焦激光束制成的“镊子”中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。 通过在高于绝对零度4度的液体制冷剂温度下运行，原子可以在陷阱中保持更长的时间，并且高度激发的原子状态，称为里德伯态，可以具有更长的寿命。 拟议的工作将研究里德堡原子的量子处理，重点是通过这些进步实现的门保真度进步。 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的组装、它们的单独控制和纠缠机制（如里德堡激发）使量子计算中可扩展和可寻址的中性原子集成为可能。 然而，由于量子相干性的多个方面的限制，进展可能很快就会饱和。 中性原子平台应该追求与目前捕获离子所提供的控制相同的控制，在某些领域甚至更好。 改进一些关键指标的一个独特途径是将中性原子嵌入低温系统中，其中原子可以潜在地存储在微观陷阱中数小时，并且黑体辐射由低温环境定义。本文介绍了一种新型的低温装置，该装置是基于一个封闭循环的低温恒温器，通过光镊保持对87Rb的单原子控制。这项工作将部署和研究这一系统，利用里德堡原子进行量子处理，重点是利用低温设备和利用单原子冷却和魔法捕获条件来提高两量子比特门的保真度。该奖项反映了NSF的法定使命，并通过使用基金会的智力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 held in traps for longer times, and highly-excited atomic states, known as Rydberg states, can have longer lifetimes. The proposed work will study quantum processing with Rydberg atoms focusing on gate fidelity advances achievable with these advances. 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. Neutral atom platforms should aspire to the same, and in some areas even better, control than is currently afforded by trapped ions. One unique path for improvement in a few of the key metrics is embedding the neutral atoms in a cryogenic system, where atoms can potentially be stored in microscopic traps for hours and blackbody radiation is defined by a low temperature environment. A new cryogenic apparatus has been developed based on a closed-cycle cryostat that retains single-atom control of 87Rb through optical tweezers. The proposed work will deploy and study this system for quantum processing with Rydberg atoms, focusing on two-qubit gate fidelity advances utilizing the cryogenic apparatus and through harnessing single atom cooling and magic trapping conditions.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.