A prototype interface between neutral-atom quantum processors and superconducting circuits

在过去的5年里，量子计算的新方法的发展取得了重大进展。也许其中最重要的是一种将单个原子用作量子比特的方法，这种方法可以使用被称为光镊子的紧密聚焦的激光光束在任意的三维几何形状中定位。这些量子比特之间的相互作用可以随意开启和关闭，方法是用额外的激光以受控的方式将它们激发到非常接近其电离极限的量子态。这些态被称为里德堡态，它们的极端性质以及它们激发的原子之间的强烈相互作用，是这种中性原子量子处理器最近快速发展的关键。中性原子量子处理器已经实现了多达200个量子比特，以解决凝聚态物理学家和材料科学家感兴趣的问题，并且存在着超越这一限制来执行更复杂的量子计算的可能性。然而，也有一个强烈的动机是开发技术来将空间上分离的中性原子处理器联网，或者将它们连接到其他量子计算平台。通过这个项目，我们将开发和演示这种量子界面的原型。这将通过在光钳中实现少量氦原子之间的量子连接来实现，并通过控制单个微波光子从一个到另一个的转移来实现超导电路。通过这项工作开发和改进的实验工具，将提供一条实现每一个更大、更复杂的量子处理器的途径，不同的组件针对不同的计算任务进行优化。

Major advances have occurred in the development of new approaches to quantum computing over the last 5 years. Perhaps the most significant of these is an approach that uses individual atoms as qubits, that can be positioned in arbitrary three-dimensional geometries using tightly-focussed laser beams known as optical tweezers. Interactions between these qubits can be turned on and off at will, by exciting them in a controlled way with additional lasers to quantum states very close to their ionisation limits. These states are known as Rydberg states and their extreme properties, and the strong interactions between atoms excited to them, have been key to the rapid recent advances in the development of this type of neutral-atom quantum processor. Neutral-atom quantum processors have been implemented with in up to 200 qubits to solve problems of interest to condensed matter physicists and materials scientists, and possibilities exist to move beyond this limit to perform more complex quantum computations. However, there is also a strong motivation to develop techniques to network spatially separated neutral-atom processors, or to link them to other quantum computing platforms. Through this project, we will develop and demonstrate a prototype quantum interface of this kind. This will be achieved by implementing a quantum link between small numbers of helium atoms in optical tweezers, and superconducting electrical circuits through the controlled transfer of individual microwave photons from one to the other. The experimental tools developed and refined through this work, will provide a path toward the realisation of every larger and more complex quantum processors, with different components optimised for distinct computational tasks.