“It was the first time I realized that quantum physics, usually expressed in neat equations and elegant theories, could also take shape in the real world,” she said. “Quantum information science was something that everybody could see and understand. Those strange ideas in quantum physics could become useful to us.”
As an undergraduate in that lecture hall, her path became clear: be part of the future of quantum information science. So she applied to the PhD program at the University of Chicago Pritzker School of Molecular Engineering (UChicago PME), where researchers work with many different kinds of qubits, the building blocks of quantum computing and communications.
“We don’t know which qubit platform will work best for quantum networking or computing, so being in an environment where I can learn from people working on all kinds of platforms gives me a much broader view,” she said. “And Chicago is an amazing place, a global hub for quantum research.”
As a graduate student in the lab of Prof. Alex High, Li is working to build scalable quantum hardware platforms using thin films of diamond. These films can host atomic-scale defects that act as qubits and can interact in a precise and controllable way, which makes them a good candidate for building a quantum network that connects to different nodes using photons.
Li has been developing a method to stretch these synthetic diamonds, which can dramatically change how the qubit behaves. It allows the qubit to perform well even at higher temperatures—something many qubit platforms cannot do—and the stretching also allows researchers to control the qubit with microwave pulses. That provides a more reliable and precise alternative to relying solely on optical control.
“Our goal is to build a powerful qubit platform that brings us closer to creating scalable quantum technology, whether that’s a global quantum network or quantum sensors or compact quantum devices for real-world use,” she said.
“In her day-to-day research, Zixi is leveraging state-of-the-art materials science, novel fabrication methods, and advanced quantum engineering to address critical scientific challenges in translating quantum discoveries to scalable technologies,” said High. “I expect her research will play a pivotal role in future, real-world quantum networks. Zixi is a true scientist at heart, and along her graduate school journey she has also shed light on the fundamental optical properties of quantum defects in diamond.”
At UChicago PME, Li has found a collaborative culture full of helpful colleagues. “Whenever I faced technical challenges in building optical and microwave set-ups, I have always been able to find someone with the right expertise to help,” she said. “I’ve also learned a lot from talking with students in other PhD tracks, like materials science, and I’ve made many friends along the way – it really feels like a community here.”
Outside of the lab, Li enjoys biking along Lake Michigan. With endless water on one side and the city skyline on the other, she feels “like a photon flying through a quantum network, both precise and full of possibility.”
“That’s why I love both biking and research,” she said. “They are both journeys. You don’t always know where they will take you, but you keep moving forward with curiosity.”
When she finishes her PhD, Li hopes to continue to develop scalable quantum hardware, ideally in academia. “I’m very proud that I’m a part of this second quantum revolution and part of this quantum hub,” she said.