Xi Wang, an assistant professor of physics, has won a Faculty Early Career Development Program (CAREER) award from the National Science Foundation (NSF) for her project “Engineering bichromatic moiré superlattices for tunable emerging quasiparticles and correlated states.” This highly competitive award is given to early-career faculty who successfully combine impactful research with mentoring and education. 

The grant will support Wang’s ongoing efforts to create new quantum structures by stacking ultrathin two-dimensional materials. Changing the orientation of the materials alters atomic interactions at the quantum level, which can generate new features such as interacting quadrupolar moiré trions, programmable quantum particles with potential applications in simulation, computing, and electronics. “We can essentially create materials that do not exist naturally to obtain the properties we’re looking for,” she said.

One of the major challenges is identifying the right materials to combine. “The candidates are required to have very similar structures,” Wang explained. “For example, if one material is a honeycomb lattice, then we need to stack it with another type of honeycomb lattice.” 

To help in her search, she collaborates with other WashU physicists, including Li Yang, the Albert Gordon Hill Professor of Physics; Professor Shaffique Adam; and Chuanwei Zhang, the Wayman Crow Professor of Physics, to identify potentially interesting materials and interactions.

“With this support from the National Science Foundation, I’ll be able to create programmable exotic quantum phenomena,” Wang said. “I’m very excited to push this work to the next level.”

The award will also support Wang’s outreach to high school students and teachers in the St. Louis area. She plans to have undergraduate students build Lego models replicating materials as seen through an atomic force microscope. The models would be used in presentations to local high schools to help students visualize how two-dimensional materials are stacked and studied. “I plan to use Lego to represent many kinds of 2D materials,” Wang said. “It would give students a hands-on way to understand the structures of these fascinating materials and the principles of atomic force microscopy.”

Wang will also hold one-day events for local high school teachers who want to learn more about quantum materials. “People can feel like there’s a big distance between physics and their daily lives,” Wang said. “By bringing frontier research into the classroom, we can help bridge that gap and inspire the next generation of scientists.”