Professor Liuyan Zhao was recently awarded a five-year National Science Foundation (NSF) CAREER award for her work on “novel magnetic phases in spin orbit coupled correlated electron systems.” The NSF CAREER award is one of NSF’s most prestigious awards. It recognizes faculty members who demonstrate the strongest foundation in research and teaching. The award supports early career faculty who show promise as strong academic role models and have the potential to become leading researchers and educators.
Professor Zhao began as a faculty member at the University of Michigan in 2017. Her research interests are in novel electronic phases in quantum materials. Quantum materials are a classification of materials with strong electronic effects. A familiar type of quantum material is a magnet, but another type, called strongly correlated systems, have been the subject of extensive research in physics. Strongly correlated systems have strong interactions between the electrons in the material, which can lead to exciting properties like superconductivity or a material transitioning from a conductor to an insulator. Within the last ten years, the class of quantum materials has grown significantly and now includes materials with strong spin-orbit coupling, where an electron’s spin is tied to its momentum. Previously, strongly correlated materials and spin-orbit coupled materials were considered to be separate, but Professor Zhao’s group instead works to understand the interaction between these two phenomena in a single material.
To study these fascinating effects, Professor Zhao and her team primarily use optical methods. One of these methods, pump-probe spectroscopy, uses a laser beam called the pump to excite the electrons in the sample. A second laser beam, called the probe, is sent in after a time delay of less than a trillionth of a second to measure the excitations produced by the pump. The tiny time scale between the pump and the probe allows for the study of excitations and particles with extremely short lifetimes. Another experimental method used by Professor Zhao’s team is nonlinear optical rotation anisotropy, which uses lasers to probe the symmetries present in a material. Learning about the symmetries could shed light on interactions between strong electronic correlations and spin-orbit coupling in the materials studied.
According to Professor Zhao, “It is not yet known what would happen upon the combination of these two aspects together, and we are driven to figure out what surprises it may produce.”