Jacob Barnhart receives DoD NDSEG Fellowship to investigate strong light-matter interactions

Jacob Barnhart, doctoral student in Electrical and Computer Engineering (ECE), has been awarded a National Defense Science and Engineering Graduate Fellowship (NDSEG) by the U.S. Department of Defense. The fellowship will support his research on quantum communications networks in the Quantum Optics Lab with Alex Burgers.

“Neutral atoms in optical tweezers are a promising platform for quantum information science. However, a large number of qubits is necessary to correct for quantum processing errors, and there are obstacles to scaling quantum system nodes,” said Barnhart. “Quantum connectivity offers the opportunity to scale and connect distinct quantum systems, enabling more advanced computing and communications.”

Barnhart aims to develop such a platform for connecting quantum systems, using microscopic pairs of mirrors called nanofabricated photonic crystal cavities (PCCs) to trap light emitted from excited ytterbium atoms. It can be hard to control photons—the smallest unit of light—in free space; by trapping them in a series of PCCs on a chip, Barnhart and Burgers will be able to manipulate them more easily and increase the interaction strength between atoms and photons.

The project aims to fabricate a series of PCCs in the Lurie Nanofabrication Facility, use an array of highly-focused laser beams called optical tweezers to capture ytterbium atoms and maneuver them over the PCCs, and then entangle the atoms. In this way, the research team will achieve multiple qubits on a single chip. Ultimately, they hope to use this technology to connect multiple chips, or quantum nodes, over a long distance using optical fibers to transfer entangled photons.

Barnhart’s work will also support the larger goals of Burger’s NSF CAREER Award.

In addition to the NDSEG Fellowship, Barnhart received the University of Michigan Rackham Merit Fellowship. Since joining ECE as a PhD student in 2023, he has presented his work at three conferences and served as an instructor for the Electrify “Entangle It” Camp, teaching high school students about quantum mechanics. Barnhart earned his undergraduate degree in Physics at the University of Washington.