One of the wonders of the late 20th century was the launch of the Global Positioning System, a constellation of 24 satellites that allows anyone with a GPS receiver to find their position on the surface of the earth. Super-accurate atomic clocks aboard the satellites have also made the system critical for synchronizing communications, the power grid, computer networks and hundreds of other applications. But GPS is not foolproof; its signal is low-power, meaning it doesn’t always work in rough terrain, and the satellites are vulnerable to all sorts of disruptions.
That’s why Jennifer Choy, an assistant professor of electrical and computer engineering at the University of Wisconsin-Madison, is using a National Science Foundation CAREER award to develop small, robust quantum sensors that could supplement or supplant GPS and help guide autonomous vehicles and people working in Earth’s most rugged environments.
“The whole theme of the project is to develop solid-state quantum technologies to potentially help with the next generation of navigation and timekeeping-based needs,” she says. “That involves developing navigational sensors in a small and reliable fashion that don’t require getting signals from GPS.”
Currently, the most cutting-edge quantum sensors measure the properties of atoms. While they are great at keeping time, and detecting acceleration and rotation, the hardware needed to contain and measure these atoms—which are typically cooled and trapped in a vacuum chamber—is large, complex, and challenging to miniaturize and integrate. Choy believes that by creating solid-state, or semiconductor-based, versions of these quantum sensors that don’t rely on cold atoms, she can make sensors small and rugged enough to work in real-world situations.
She will use “color centers,” a special type of defect in diamond crystals that mimic trapped atoms and ions, to develop magnetic navigation sensors and quantum gyroscopes. She also plans to explore similar defects in silicon-based materials for developing quantum clocks which can provide accurate timing and be integrated on a computer chip.
As part of the outreach element of the project, Choy also plans to design new undergraduate courses on quantum sensing and create quantum education content for high-school students, such as student research projects through collaboration with high-school teachers and low-cost activity kits for teaching quantum and optical science.