Distinguished Seminar Series Sponsored by the Texas Quantum Institute (TQI) with Dongxia Qu with the Lawrence Livermore National Laboratory
Nov
4
2026
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Dongxia Qu
Nov
4
2026
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Dongxia Qu
Description
Topological circulators based on quantum anomalous Hall (QAH) materials provide a promising route toward compact,
magnet-free, and potentially low-loss nonreciprocal devices for quantum information processing and sensing. In this
talk, I will present our recent progress in developing and understanding topological circulators formed by coupling QAH
devices to microwave resonators. We demonstrate pronounced nonreciprocal microwave transmission and strong
hybridization between QAH edge modes and a microwave resonator, with a measured coupling strength exceeding the
dissipation rates of the coupled system. By tuning the drive conditions, the device exhibits frequency-selective
responses, mode hybridization, and non-Hermitian behavior, including features associated with exceptional points.
These effects provide a versatile platform for studying the interplay among topological transport, microwave photons,
and engineered dissipation. Beyond their role as passive nonreciprocal components, these coupled topological devices
offer opportunities for integrated quantum readout, microwave routing, and sensing architectures. Together, these
results highlight topological circulators as a promising platform for quantum-device engineering and for exploring
emergent microwave phenomena in topological materials.
About the Speakers
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Dongxia Qu
Lawrence Livermore National Laboratory
Dongxia Qu is a staff scientist in the Materials Science Division at Lawrence Livermore National Laboratory (LLNL). She received her B.E. from Zhejiang University in China, and her M.A. and ...
Dongxia Qu is a staff scientist in the Materials Science Division at Lawrence Livermore National Laboratory (LLNL). She received her B.E. from Zhejiang University in China, and her M.A. and Ph.D. from Princeton University. After earning her Ph.D., she joined LLNL in 2012 as a postdoctoral researcher in the Condensed Matter and Materials Science Division and became a staff scientist in 2015. Her research focuses on topological quantum materials and devices for quantum information applications. She has served as a principal investigator on multiple Laboratory Directed Research and Development (LDRD) projects and U.S. Department of Energy High Energy Physics research and development projects.
Location
EER 3.640
For any questions or Zoom link access, please contact Kamela Syed at kamela.syed@austin.utexas.edu