CAREER: Quantum Computing with Circular Rydberg Atoms

Princeton University, Princeton NJ

Investigators

Abstract

Coherent, programmable quantum systems have enabled fundamental advances in our understanding of quantum dynamics and quantum technologies including quantum computing, sensing and networks. Arrays of individually trapped, laser-cooled atoms are a leading experimental implementation of programmable quantum systems in the lab. In this project, the PI aims to advance the state of the art in this field by studying new types of atomic states, called circular Rydberg states, which are believed to perform better because of their extremely long lifetimes. However, techniques to efficiently create, manipulate and measure these states are largely unexplored. The PI will carry out fundamental investigations of these states and their properties, as well as their application to both fundamental science and technology. Additionally, this research will provide valuable scientific training for undergraduate and graduate students in physics and engineering. Rydberg atom arrays are a leading platform for quantum computing and simulation, combining strong, long-range interactions with highly coherent operations and flexible geometries. Despite recent improvements, achievable fidelities are limited by technical imperfections and the finite lifetime of the Rydberg states. In this work, the PI proposes a novel approach to Rydberg atom arrays based on long-lived circular Rydberg states in optical traps. The low efficiency of exciting circular states is overcome using a quantum nondemolition measurement-based rearrangement scheme, and local manipulation of circular states is performed using the ponderomotive potential of focused Laguerre-Gauss beams. Based on the extremely long lifetime of these states (exceeding seconds in cryogenic microwave cavities) and robust control techniques, the PI projects that arrays of up to one thousand circular Rydberg atoms with two-qubit gate errors in the part-per-million range can be realized using current technology. This is a significant improvement on the current state-of-the-art in any quantum computing or simulation platform. 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.