Professor
Office: 237 Physics Building
Phone: +1 (530) 752-4689
Fax: +1 (530) 752-4717
Email: xdzhu@ucdavis.edu
Personal Professional Website:
http://zhu.physics.ucdavis.edu
Research Interests:
Professor Zhu joined the Physics Department in 1989. He is a fellow of American Physical Society since 2007 and a fellow of Optical Society of America since 2011. His research activities are focused on the development and application of optics-based techniques to investigation of structures and processes on solid surfaces such as magnetism, mass transport, material growth and erosion, and biomolecular interactions. His recent interests include (1) studies of magneto-optic effects in unconventional materials such as topological insulators with oblique-incidence Sagnac interferometry and reflectometry using balanced photodiode bridge; (2) in situ studies of polarization catastrophe and defects in ultrathin oxide films using oblique-incidence reflectivity difference ellipsometry; (3) high-throughput characterization of kinetics and functionality of biomolecular reactions using oblique-incidence reflectivity difference scanning ellipsometry.
Time-reversal symmetry breaking effects in unconventional materials – Magnetism is one of fundamental properties of materials. Interests in new magnetic phases and spin transport in materials of low dimensionality and in topologically distinct materials such as topological insulators drive and expand the field of magnetism. Since magnetism in a material breaks the time reversal symmetry, its presence and character reveal themselves through the magneto-optic effect when the material interacts with light. Professor Zhu’s group develops a range of magneto-optic probes such as oblique-incidence zero-area Sagnac interferometry, oblique-incidence reflectometry with a balanced photodiode bridge, and polarization-modulated reflectometry. The research is focused on detection of magnetic skyrmions, characterization of spin polarization in topological insulators and magnetic signatures in other unconventional materials.
Thin Film Growth – Growth and functionality of materials involve understanding and control of molecular constituents on solid surfaces at the unit cell level. Characterization of materials during fabrication at such a level presents a major challenge in material science and condensed matter physics. This challenge fuels efforts in development of new experimental techniques that meet the challenge in one aspect or another. Professor Zhu's group focuses on development and application of optics-based techniques for characterization of molecular constituents on a solid surface during material growth by exploring the correlation between properties of a reflected light and those of molecular constituents on the solid surface.
Simultaneous Detection of 10,000 Biomolecular Reactions on Solid Support – Based on measurements of oblique-incidence reflectivity difference (OI-RD), Professor Zhu’s group developed a platform that detects over 10,000 biomolecular reactions on a solid surface in real time. It enables simultaneous, comparative studies of the interaction of a DNA fragment or a protein molecule or a viral particle or a bacterium with a large number of distinct molecular targets from compound libraries of National Institutes of Health (~ 500,000 to 1,000,000 compounds), National Cancer Institute (~ 100,000 compounds), and commercial vendors (~ 1,000,000 or more compounds). The platform promises to significantly advance genomic and proteomic research and discovery of new drugs.
Research Areas
Career History
- Ph.D., University of California, Berkeley, 1989
- Assistant Professor, University of California, Davis, 1989-1993
- Associate Professor, University of California, Davis, 1993-1998
- Professor, University of California, Davis, 1998-Present
Honors
- Fellow, Optical Society of America, 2011
- Fellow, American Physical Society, 2007
- Overseas Chinese Young Scientist Award (Chinese Natural Science Foundation), 2000
- Adjunct Professor of Physics, Institute of Physics, Chinese Academy of Sciences, 2001