学术活动
光学
Non-Abelian Braiding with Sound and Light
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主讲人: 马冠聪 副教授, 香港浸会大学
地点: 腾讯会议ID:612-695-865
时间: 2022年10月5日 (星期三) 15:10-18:00
主持 联系人: 胡小永(Tel: 62768705)
主讲人简介: Dr. Guancong Ma is currently an associate professor in the Department of Physics, Hong Kong Baptist University. Dr. Ma received a B.Sc. in applied physics at the South China University of Technology in 2007, and then a Ph.D. in physics at Hong Kong University of Science and Technology in 2012. After that, he became a postdoc fellow in the Institute for Advanced Study and Department of Physics, Hong Kong University of Science and Technology until 2017. He joined the Department of Physics, Hong Kong Baptist University as an assistant professor until the promotion in 2021. He now serves as a member of the Executive Committee of the Physics Society of Hong Kong. Dr. Ma’s research currently focuses on studying topological physics and non-Hermitian physics in using acoustic-wave platforms. He is also interested in metamaterials and complex waves. He has published over 40 paper on peer-reviewed journals, including Science, Nature, Nature Materials, Nature Physics, Physical Review X, Physical Review Letters. He has also published a review article on acoustic metamaterials in Science Advances (2016), and a review article on topological acoustics and mechanics in Nature Reviews Physics, which is selected as part of NatureResearch’s themed article collection titled “40 years of quantum Hall effect”. Dr. Ma also holds 9 patents from the US and China. Dr. Ma is listed among the “World’s Top 2% Scientists” by Clarivate. Dr. Ma was the recipient of the “C. N. Yang Award” by the Association of Asia Pacific Physical Societies and the Asia Pacific Center for Theoretical Physics, and was one of the “Top 10 Rising Star in Science and Technology 2021” by the China Association for Science and Technology. In 2019, Dr. Ma has obtained support from the National Natural Science Foundation of China’s Excellent Young Scientists Scheme (Hong Kong & Macao).

Non-Abelian-based theories are one of the foundations of modern physics. For example, non-Abelian braiding realized by the dynamic winding ofanyonsis widely considered an important candidate for quantum computers. Operations defined by non-Abelian groups are noncommutative in character, meaning that the outcomes of sequential operations depend on their orders. Non-Abelian processes are mathematically captured by unitary matrices, which can manifest as a Berry-phase matrix that connects holonomic adiabatic evolutions of multiple states in parameter space. Because the Berry phase is pervasive in a wide variety of systems, non-Abelian operations are realizable in classical waves such as sound and light. In this talk, I will present our recent findings in classical-wave non-Abelian operations. I will discuss the realization of non-Abelian braiding in acoustics and photonics. Here, the braiding operations are implemented using coupled waveguide arrays, which are adiabatically modulated to enforce a multi-state Berry-phase matrix that swaps the modal dwell sites. The non-Abelian characteristics are revealed by switching the order of two distinct braiding operations involving at least three modes.