题目： Computational Electromagnetics, Wave Physics and Quantum
Mechanics
报告人： 周永祖教授
(香港大学工学院院长)
时 间： 2010年5月21日下午14：30-16：00
地 点： 东南大学吴健雄纪念馆报告厅
主办单位: 东南大学毫米波国家重点实验室
IEEE AP-MTT-EMC Joint Nanjing Chapter
江苏省电子学会天线与微波专委会
内容简介：
In the beginning, electromagnetic analyses, like many science and engineering analyses, were done with pencils and papers. Closed form solutions were sought. Later on, approximate solutions were sought. With the advent of computers, computer solutions were sought. This development not only happens in electromagnetics, but in other fields in engineering and science, such as computational mechanics, fluid dynamics, and physics. Nowadays, computational electromagnetics replaces pencil and paper analyses.
Computational electromagnetics has changed how modern-day scientists and engineers work as electromagnetic simulation tools are used as a virtual laboratory where ideas can be tested, and virtual proto-typing can be performed.
Unbeknownst to many, much physical insight of wave and field physics is needed in order to design fast and efficient algorithms for computational electromagnetics. We will discuss some of the pertinent physics involved relevant to the design of fast computational algorithms. For instance, wave field is oscillatory and static field in smooth. This difference has affected the development of fast algorithms for computational electromagnetics: it is a lot easier to accelerate static field calculation, but very difficult to develop fast algorithms for wave physics problems.
While wave physics is important in electromagnetics, it is also important in many modern physical concepts such as mesoscopic physics, coherence and decoherence in quantum systems, and Casimir force calculation. When the dimensions of electronic devices are on the order of the mean free path of the electrons, wave physics and interference phenomenon are important in describing the behavior of electrons in these mesoscopic scale devices. Another wave physics phenomenon that appears in quantum physics is the concept of coherence and decoherence. For instance, this concept is important in optics in the electromagnetic spectrum because of the short wavelength at optical frequencies. Due to the high momentum of electrons, the electronic wavelength is much smaller than optical wavelength. This makes the coherence length of electrons to be much smaller than those in optics. As a result, a quantum system becomes decoherent rapidly. Again, a quantum system can never be isolated, and the coupling of one quantum system to another rapidly decohere a quantum state. Hence, the design of quantum computers is extremely difficult. Lastly, the meaning of nothingness does not exist in quantum electromagnetics, because there is fluctuating electromagnetic field even in vacuum where classical electromagnetics implies zero field. The vacuum fluctuation gives rise to attractive forces between objects that are in close proximity to each other. We will show some calculations of Casimir force using combination of computational electromagnetics, statistical physics, and quantum electromagntics.
报告人简介：
Weng Cho Chew received the B.S. degree in 1976, both the M.S. and Engineer’s degrees in 1978, and the Ph. D. degree in 1980, all in electrical engineering from the Massachusetts Institute of Technology, Cambridge, MA.
He is serving as the Dean of Engineering at The University of Hong Kong. Previously, he was a professor and the Director of the Center for Computational Electromagnetics and the Electromagnetics Laboratory at the University of Illinois. Before joining the University of Illinois, he was a department manager and a program leader at Schlumberger-Doll Research. He served on the IEEE Adcom for Antennas and Propagation Society as well as Geoscience and Remote Sensing Society. He has been active with various journals and societies.
His research interests are in the areas of waves in inhomogeneous media for various sensing applications, integrated circuits, microstrip antenna applications, and fast algorithms for solving wave scattering and radiation problems. He is the originator several fast algorithms for solving electromagnetics scattering and inverse problems. He has led a research group that has developed parallel codes that solve dense matrix systems with tens of millions of unknowns for the first time for integral equations of scattering.
He has authored a book entitled Waves and Fields in Inhomogeneous Media, coauthored a book entitled Fast and Efficient Methods in Computational Electromagnetics, authored and coauthored over 300 journal publications, over 400 conference publications and over ten book chapters.
He is an IEEE Fellow, an OSA Fellow, an IOP Fellow, and was an NSF Presidential Young Investigator (USA). He received the Schelkunoff Best Paper Award for AP Transaction, the IEEE Graduate Teaching Award, UIUC Campus Wide Teaching Award, IBM Faculty Awards. He was a Founder Professor of the College of Engineering, and currently, a Y.T. Lo Endowed Chair Professor in the Department of Electrical and Computer Engineering at the University of Illinois. From 2005 to 2007, he served as an IEEE Distinguished Lecturer. In 2002, ISI Citation elected him to the category of Most-Highly Cited Authors (top 0.5%). In 2008, he was elected by IEEE AP Society to receive the Chen-To Tai Distinguished Educator Award.
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