Abstract
(Joint work with Prof Vadim Markel, University of Pennsylvania)
Nontrivial magnetic response of periodic structures composed of intrinsically nonmagnetic constituents is now a well-established but still intriguing phenomenon; it plays a critical role in negative refraction, cloaking and other unusual effects. Much attention has been devoted to optimal (in some sense) design, whereby the magnetism would be enhanced and engineered to fall in a desirable range for specific applications – absorption, cloaking, lensing, etc. However, the speaker and his research group show both analytically and numerically that this artificial magnetism has principal limitations: the stronger the magnetic response (as measured by the deviation of the effective permeability tensor from identity), the less accurate (“certain”) predictions of the effective medium theory are. The speaker and his research group view this as an uncertainty principle for the effective parameters of metamaterials.
This analysis is closely related to, but logically independent from, the recently developed non- asymptotic homogenization theory for periodic electromagnetic structures (Proc. R. Soc. A, 2014.0245). In that theory, no assumptions other than the intrinsic linearity of the constituent materials of the structure are made; in particular, anisotropy and magnetoelectric coupling may exist, and the lattice cell size does not need to be vanishingly small.
Numerical examples are given and a clear distinction between classical (asymptotic) and non-asymptotic homogenization theories is drawn.
About the speaker
Prof Igor Tsukerman received his combined BS / MS degree in Control Systems in 1982 and his PhD degree in Electrical Engineering in 1988 from St. Petersburg Polytechnic in Russia. Prof Tsukerman worked at the Department of Electrical & Computer Engineering in the University of Toronto from 1990 to 1995. He joined the University of Akron in 1995 and is currently the Professor of Electrical and Computer Engineering. His research areas are applied electromagnetics and photonics, simulation of nanoscale systems, finite element and finite difference analysis.
Prof Tsukerman has authored or co-authored about 150 refereed publications and two books. His research has been supported by the National Science Foundation (NSF), the Natural Sciences and Engineering Research Council of Canada (NSERC), US Air Force, Army Research Office, the Defense Advanced Research Projects Agency (DARPA), and by industry (ABB, Rockwell Automation, NEC, Baker Hughes, General Electric, Structural Research & Analysis Corp., 3ga Corp.).
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