报告题目：Electron Sociology – An Introduction to Condensed Matter Physics
报 告 人：Congjun Wu （Westlake University）
What is condensed matter physics? What are its style and philosophy? Its old name was solid state physics. Particles in solids are well-known (e.g., electrons, molecules, and ions), and interactions among them are unsurprising either (e.g. Coulomb interaction and others derived from it.). Compared to high energy physics, condensed matter physics certainly obeys the laws of high energy. Then is condensed matter physics still fundamental, or, is it mostly an applied one? If using only one sentence to express the spirit of each branch of modern physics, I would say and I wish people from these fields agree: High energy physics studies the fundamental interactions at the smallest scales of space-time; Astrophysics studies the birth and evolution of the universe at the largest scales of space-time; for Atomic, Molecular and Optical physics, it aims at achieving the finest levels of controllability. Then what should we say for Condensed Matter Physics? I will address these questions in this talk.
According to the classic work by P. W. Anderson “More is different”, we could say that Condensed Matter Physics is the sociology of a large amount of particles (e.g. electrons), and seeks for the underlying organizing principles of matter. Condensed matter systems are highly organized societies, and electrons are their citizens. They not only compete, but also collaborate, developing rich social structures such as superconductivity and magnetism, which can be precisely described by advanced mathematical and physical methods. Manifestations of the sociality nature of electrons is the new physics from the condensed matter perspective, which cannot be derived from the basic laws of high energy but must be viewed as new fundamental principles.
Ref: P. W. Anderson, “More is different”, New Series, Vol. 177, No. 4047 (Aug. 4, 1972), pp. 393-396
Congjun Wu received his Ph.D. in physics from Stanford University in 2005, and did his postdoctoral research at the Kavli Institute for Theoretical Physics, University of California, Santa Barbara, from 2005 to 2007. He became an Assistant Professor in the Department of Physics at the University of California, San Diego (UCSD) in 2007, an Associate Professor of Physics at UCSD in 2011, and a Professor of Physics at UCSD in 2017. In 2021, he joined the Westlake University as a chair Professor of Physics. He received the Sloan Research Fellowship in 2008, and the “Outstanding Young Re-searcher Award” of Overseas Chinese Physics Association in 2008. He was elected to be a Fellow of American Physical Society in 2018. His research interests are exploring new states of matter and reveling their organizing principles, including quantum magnetism, superconductivity, topological states, mathematical physics, and the numerical method of quantum Monte Carlo simulations.