Extremely precise quantum sensors promise to be a transformative technology with a variety of potential applications. For example, quantum sensors could advance neuroimaging by allowing researchers to detect nanoscale changes in electromagnetic fields in the brain with incredible precision.
This technology harnesses unique attributes of quantum mechanics, which describes the behavior of atoms and subatomic particles.
“At the heart of how these quantum sensors work is the interaction between discrete electronic energy levels of quantum systems and their environment,” says Jennifer Choy, who joined the Department of Engineering Physics as an assistant professor in January 2019. “We’re essentially using these interactions to precisely and sensitively measure physical quantities such as electric and magnetic fields, and inertial motion.”
Photons play a crucial role in characterizing and manipulating quantum systems, and that is why Choy’s research focuses on engineering interactions between light and matter in atoms and atom-like systems.
Choy says developing methods to control photons and their interactions with these atomic systems will enable better understanding and control of quantum properties, and improve the performance and utility of quantum sensors.
“I’m interested in drawing on the wealth of research already happening in nanoscale optics and photonic engineering to enable more efficient measurement and control of quantum systems, and develop more compact and robust atom-based instruments,” says Choy, who is also a Grainger Institute for Engineering fellow.
One type of quantum system Choy studies involves single atomic-scale defects trapped inside of diamonds. “These defects can behave like atoms in the sense that they have isolated electronic energy states that you can probe with spectroscopy,” says Choy. “These systems are promising for sensing applications because you can engineer the environment around the defect and use it as a nanoscale probe that can be placed very close to the object that you want to sense, such as a neuron.”
Choy earned her PhD in applied physics from Harvard University. Prior to joining UW-Madison, she was a principal member of technical staff at Draper Laboratory, a nonprofit research and development organization in Cambridge, Massachusetts, where she developed atomic and optical inertial sensors for precision navigation, which could be useful for defense applications.
“Working at Draper was a really valuable learning experience for me, but ultimately I’m excited to work with students both in the context of research advising as well as classroom instruction,” she says.
While quantum research as a discipline is often based in physics departments, Choy believes the engineering physics department will be a great home for her research.
“I think there are a lot of quantum technologies that can bear fruit in the near term and can really benefit from an engineering approach, and in particular a pan-disciplinary program such as engineering physics at UW-Madison, which has a history through the nuclear engineering track of combining very fundamental research with challenging engineering to assemble fully functional systems,” she says.
Choy is excited to collaborate with faculty not only in the College of Engineering but across the university. Opportunities for collaboration are growing as UW-Madison has been making significant investments in quantum science and technology—including joining the Chicago Quantum Exchange in February 2019. The CQE—a partnership anchored at the University of Chicago and which includes the University of Illinois at Urbana-Champaign, the U.S. Department of Energy’s Argonne National Laboratory and the Fermi National Accelerator Laboratory—is a hub for the research and development of quantum technology. Choy is among the UW-Madison faculty who will be contributing expertise and collaborating within the CQE.
In spring 2019, Choy is teaching a lab course on nuclear instrumentation (NE 427). “It’s exciting because I think lab experience is very critical to any training in science and engineering,” she says. “I think lab courses are important because they encourage students to take an active role in learning through hands-on experiences.”
Author: Adam Malecek