Fast quantum logic gates using optically trapped neutral atom arrays

将受控量子动力学应用于计算问题是近二十年来信息科学领域最重要的发展之一。本项目研究使用中性Rb原子的光学捕获阵列来创建多量子位量子信息处理器。聚焦的激光束将被用来操纵原子的量子态。内部基态之间的单量子比特旋转将由光激发的拉曼跃迁来完成。双量子位条件逻辑运算将通过将原子耦合到高激发里德伯态来实现。中性原子的里德伯态具有强的偶极-偶极相互作用，为高保真的快速条件逻辑门提供了一种机制。预计单量子比特门和双量子比特门的速度将超过1mhz。利用里德伯相互作用进行单原子的确定性加载，这将导致可扩展的多量子位器件也将进行实验研究。作为这项工作的一部分，将获得关于强相互作用里德伯原子动力学的新知识。该项目包括高速里德伯态激发和低退相干光学陷阱的新技术发展，这将推进冷原子外部和内部状态的光学操纵的最新技术。这项工作的广泛影响是双重的。首先，这项研究是实现超越传统经典计算机能力的大规模量子处理器梦想的重要一步。这种设备的可用性将对数值数学、信息安全以及与开发新的、技术上有价值的材料相关的量子系统模拟问题产生深远的影响。第二，该研究项目将有助于培养科学和工程领域的学生和博士后研究人员。来自不同背景的人们将接受现代实验科学的教育和培训，以及在物理学和信息科学之间架起桥梁的抽象概念。培训将通过课程丰富和直接参与我们大学的研究项目来进行。我们还将向当地社区介绍物理学对信息技术的重要性，以及量子信息科学领域的新发展。物理系的公众参观日、实验室之旅和教师对当地学校的访问将促进对公众的宣传。

The application of controlled quantum dynamics to computational problems has been one of the most important developments in information science in the last two decades. This project studies the use of optically trapped arrays of neutral Rb atoms for creating a multi-qubit quantum information processor. Focused laser beams will be used to manipulate the quantum states of the atoms. Single qubit rotations between internal ground states will be performed by optically stimulated Raman transitions. Two-qubit conditional logic operations will be performed by coupling the atoms to highly excited Rydberg states. The Rydberg states of neutral atoms have strong dipole-dipole interactions which provide a mechanism for fast conditional logic gates with high fidelity. It is projected that single and two-qubit gates will be possible at speeds greater than 1 MHz. The use of Rydberg interactions for deterministic loading of single atoms which will result in a scalable multi-qubit device will also be studied experimentally. As part of this work new knowledge will be gained on the dynamics of strongly interacting Rydberg atoms. The project includes new technical developments in high speed Rydberg state excitation and low-decoherence optical traps which will advance the state of the art for optical manipulation of the external and internal states of cold atoms. The broader impacts of this work are twofold. First, this research is an important step towards realizing the dream of a large scale quantum processor that exceeds the capabilities of conventional classical computers. The availability of such a device will have far reaching impact on numerical mathematics, information security, and problems in the simulation of quantum systems related to the development of new, technologically valuable materials. Second, the research program will contribute to the training of students and postdoctoral researchers for careers in science and engineering. People from diverse backgrounds will be educated and trained in modern experimental science, as well as in abstract concepts that bridge the boundary between physics and information science. Training will occur via curriculum enrichments, and through direct participation in our University based research program. We will also inform the local community about the importance of physics to information technology, and the new developments in the area of quantum information science. Outreach to the public will be facilitated by public visiting days at the Physics department, laboratory tours, and faculty visits to local schools.