RUI: optical tweezer array for tripartite rydberg entanglement

The National Science Foundation Division of Physics awarded Kenyon College $234,667 on August 1, 2026, under the Mathematical and Physical Sciences program (CFDA 47.049) to develop optical tweezer arrays for tripartite Rydberg entanglement in neutral atom quantum computing research.

The project will explore methods to make three Rydberg atoms interact coherently through two approaches: applying rapid microwave-induced state changes to Rydberg atoms, and creating optical tweezer arrays to trap three single atoms while isolating interactions with unwanted neighboring atoms. The work builds on prior demonstrations of coherent control of three-atom entangled states in bulk gas; the project aims to extend and refine these capabilities for potential applications requiring multi-body interactions in neutral atom quantum computers. The research will also provide deep and meaningful research experiences for undergraduate students, contributing to the nation's quantum workforce.

Performance takes place in Gambier, Ohio, over the period August 1, 2026 through July 31, 2029.

Abstract

There has been an explosion of recent progress in neutral atom quantum computers. In these devices, single units of information, or qubits, are encoded in the states of individual atoms. Because the atoms have no net charge, one can put many in close proximity without disturbing one another. However, to perform a computation one needs to make these neutral atoms interact. This is done by exciting an electron in the atom to a high energy, or rydberg, state. The strong interactions between pairs of rydberg atoms are the key to most of today?S neutral atom quantum computers. However, new advances may require interactions between three or more rydberg atoms. The PI and coworkers will explore ways to make three rydberg atoms interact coherently, or reversibly. They will do this in two ways. First, by making fast changes to the states of rydberg atoms using microwave radiation. Second, by creating an array of ?tweezers? To trap three single atoms and remove the confounding effects of interactions with unwanted neighbors. This work may lead to new advances in neutral atom quantum computers. IT will also contribute to our nation?S quantum workforce, by providing deep and meaningful research experiences for undergraduate students. Neutral atom quantum computers have advanced rapidly, owing to coherent control of single atoms in optical tweezer arrays. To generate entanglement and perform quantum gates, one exploits pairwise interactions among highly-excited, or rydberg, states. However, new applications may require multi-body interactions. By carefully choosing the laser parameters when exciting atoms to a target rydberg state near an interaction, or F?rster, resonance one may excite entangled states of three rydberg atoms. In previous work, the PI and coworkers demonstrated coherent control of these three-atom entangled states in a bulk gas. The coherence times were of order hundreds of nanoseconds. The PI and collaborators will develop more sophisticated methods for control and extend the coherence time. First, they will perform coherent manipulations by driving high-rabi-frequency microwave transitions in the rydberg manifold. This will allow pulse sequences tailored to coherently cancel the effect of dipole-dipole interactions between a three-atom state and a background of rydberg atoms. Second, they will develop a three-trap optical tweezer array. This will allow them to isolate three single atoms, and study in detail the ways they interact. Such a system will be the first of its kind at a liberal arts college. The training students receive will contribute to the development of a strong national quantum workforce. 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.- subawards are not planned for this award.