Fast quantum logic gates using optically trapped neutral atom arrays

受控量子动力学在计算问题中的应用是近二十年来信息科学最重要的发展之一。本项目研究使用光学捕获的中性Rb原子阵列来创建多量子比特量子信息处理器。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通过光激拉曼跃迁来执行。双量子位条件逻辑运算将通过将原子耦合到高度激发的里德堡态来执行。 中性原子的里德伯态具有很强的偶极-偶极相互作用，这为高保真度的快速条件逻辑门提供了一种机制。据预测，单量子位和双量子位门的速度将超过1 MHz。使用里德伯相互作用的确定性加载的单原子，这将导致一个可扩展的多量子比特设备也将进行实验研究。 作为这项工作的一部分，新的知识将获得强相互作用的里德伯原子的动力学。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，这将推动冷原子外部和内部状态的光学操纵的最新技术水平。这项工作的广泛影响是双重的。首先，这项研究是实现大规模量子处理器梦想的重要一步，这种处理器的能力超过了传统经典计算机。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、有技术价值的材料相关的量子系统模拟问题产生深远的影响。其次，该研究计划将有助于培养学生和博士后研究人员从事科学和工程职业。 来自不同背景的人将接受现代实验科学以及弥合物理学和信息科学之间边界的抽象概念的教育和培训。培训将通过课程丰富，并通过直接参与我们的大学为基础的研究计划。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。 与公众的联系将通过物理系的公众访问日、实验室图尔斯参观和教师对当地学校的访问来促进。

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.