Abstract: The unexpected discovery of superconductivity and strong electron correlation in twisted bilayer graphene, a system composed solely of 𝑠-𝑝 electrons, stands as one of the most intriguing developments in two-dimensional materials in recent years. A key feature of this system is the emergence of flat energy bands near the Fermi level (a condition that promotes the formation of novel many-body phases) at the so-called “magic angles.” Gaining a deeper understanding of the physical origin of these flat bands is essential for constructing an effective theory of unconventional electron correlation. In this talk, I will present our recent theory on the origin of these magic angles in twisted graphene layers and their connection to the Fermi ring in AA-stacked multilayer graphene.

Biography: Dr. Mei-Yin Chou specializes in theoretical condensed matter physics, focusing on the electronic properties of novel materials with both fundamental and technological significance. She earned her Ph.D. in Theoretical Condensed Matter Physics from the University of California, Berkeley, in 1986. Following a postdoctoral fellowship at Exxon Research and Engineering Company in New Jersey, she joined the School of Physics at the Georgia Institute of Technology in 1989. She served as the ADVANCE Professor of Science from 2002 to 2006 and as Chair of the School of Physics from 2005 to 2010. In January 2011, she became a Distinguished Research Fellow at Academia Sinica in Taiwan. She was Director of the Institute of Atomic and Molecular Sciences from 2011 to 2016 and was appointed Vice President of Academia Sinica in 2016.

Dr. Chou received the Alfred P. Sloan Research Fellowship (1990-1992), the David and Lucile Packard Fellowship (1990-1995), and the Presidential Young Investigator Award from the National Science Foundation (1991-1996). She was elected Fellow of the American Physical Society in 2002 and Academician of Academia Sinica in 2014. Since 2008, Dr. Chou has served on the Editorial Board of the UK journal Reports on Progress in Physics. She was elected to serve as Chair of the Division of Computational Physics of the American Physical Society (APS) in 2008, and was Chair for the C20 Commission on Computational Physics within the International Union of Pure and Applied Physics (IUPAP) in 2022-2024.