Assistant Professor Joon Sue Lee has won a prestigious CAREER award from the National Science Foundation (NSF) to advance the creation of quantum materials for new quantum devices. He is the ninth member of the current physics faculty to win this award and one of three recent UT recipients.

Atomic-Scale Engineering

The NSF CAREER program supports early-career faculty with the potential to be academic role models in research and education. Since joining the department in 2020, Lee has won back-to-back teaching awards and built a research group that specializes in developing quantum materials, especially those with potential applications in quantum technologies.

The transistors and semiconductors that power smartphones and biosensors were built on understanding electrical properties. Future quantum technologies rely on the fascinating but atypical workings of quantum mechanics. In systems so small they’re measured in atoms, the physics tends to go off script. Particles can be in multiple states at the same time or they may be entangled. Properties don’t exist until they’re measured. Lee’s work navigates through this landscape to make new materials and devices for a modern world. With this NSF support, he’ll focus on a single-element material—tin (Sn)—because it has a dramatically different personality.

“Tin has two different structures,” he said. “Alpha phase is topological. Beta phase is superconducting. If you can control the growth of each phase, then you can control the electrical properties.”

Superconductivity allows electrical current to flow with no resistance. Topological phases, on the other hand, are defined by the global arrangement of a material’s electronic wavefunctions—its band topology. In conventional materials, the conduction and valence bands remain distinct. However, in topological materials, these bands can invert due to strong spin-orbit coupling.

“This inversion changes the material’s topological order, creating protected surface or edge states that allow electrons to travel without scattering,” Lee explained.

Such states are remarkably robust against defects and impurities, giving rise to exotic behaviors that bridge fundamental quantum physics and potential device applications. Combining superconductivity and topology gives scientists exciting opportunities for new technologies.

“Topological superconductivity, for example, is one of the most promising routes toward quantum computing,” Lee said. “That’s one of the big motivations.”

Using the Molecular Beam Epitaxy resources at UT’s Institute for Advanced Materials, Lee grows thin films, one layer of atoms at a time, on crystalline substrates. His goal is to selectively grow pure superconducting and topological phases of tin and put them together into structures with “atomically precise” interfaces.

“If we can achieve that, then we will be able to design materials where one area has one structure and the adjacent area has the second structure,” he said.

By adjusting the lattice parameters of underlying buffer layers of those areas, he can tune the tin phases and control their electrical properties.

“We want to explore the basic physics in these electrical states,” he said, “and also develop devices that could lead to future quantum applications.”

Professor and Department Head Adrian Del Maestro said that “Lee’s work harnesses the quantum behavior of materials for new technologies, including novel superconductors that can be used for sensing and energy applications. His lab is always bustling with undergraduate and graduate students, where he is training the workforce of tomorrow.” 

The work aligns well with the university’s strategic focus on advanced materials and manufacturing innovation gateway, part of a concentrated effort to make the most of UT’s expertise to tackle grand challenges. Lee, who has won teaching awards from the College of Arts and Sciences and the UT Alumni Association, also plans to share this research with undergraduates to inspire a new generation of scientists.

“I plan to use the data from our samples to explain or demonstrate superconductivity or topological properties in class,” he said. He added that he can also use semiconductors and insulators in his lab and “those can help students understand electrical properties of different materials.”

Lee’s five-year project began in August and includes $749,441 to support his work. He is the ninth member* of the current physics faculty to win an NSF CAREER award. The program has supported the department’s wide range of expertise, including research in condensed matter, elementary particles, biophysics, and nuclear theory.

*Adrian Del Maestro, Steven Johnston, Larry Lee, Jian Liu, Norman Mannella, Jaan Mannik, Lucas Platter, and Haidong Zhou have all won NSF CAREER Awards.

Graduate Student Pradip Adhikari joined Joon Sue Lee’s research group in the fall of 2020 and is one of 11 graduate students to win a Graduate Advancement, Training, and Education (GATE) Award for the 2025-2026 academic year. These awards from the UT-Oak Ridge Innovation Institute’s Science Alliance support collaborative research between the university and Oak Ridge National Laboratory, providing outstanding graduate students with a 12-month appointment including a stipend, tuition, and benefits.

While he isn’t working directly on the NSF CAREER research, Lee explained that “in Pradip’s case, he’s using a different material system (but) it’s the same motivation; the same big idea about topological materials and superconductivity.”

Adhikari’s project is the device-scale interplay of unconventional superconductivity and magnetism. While they typically have an adversarial relationship (usually leading to the suppression of one state by the other) he is working with a combination of iron, tellurium, and selenium, or FeTeSe, which is a notable example of an unconventional superconductor with co-existing superconductivity and magnetism.

“The interplay of topology, magnetism, and superconductivity gives rise to exotic and robust quantum states, making such materials a fertile ground for discovering new physics,” Adhikari said. “My research interest lies in the synthesis of high-quality topological materials, fabricating devices from them, and studying their properties at the device scale. I am particularly excited by how the unique electronic behaviors of these materials can be explored and harnessed for next-generation quantum technologies.”