For More Information:
301 405 3596
Plasmon Resonances in Nanoparticles
Prof. Isaak Mayeroyz
Electrical and Computer Engineering Department
University of Maryland
September 28, 2007, 2:00 p.m.
Jeong H. Kim Engineering Building, Rm. 1110
ABSTRACT: It is known that metallic nanoparticles can exhibit resonance behavior at certain frequencies for which their permittivity is negative and the free-space wavelength is large in comparison with their dimensions. This phenomenon usually occurs at nanoscale and at optical frequencies where the above two conditions can be simultaneously and naturally realized. These resonances result in powerful localized sources of light, which have numerous promising applications in nano-lithography, nanophotonics, surface-enhanced Raman scattering, biosensors, optical and magnetic data storage, etc. Currently, these resonances are by and large studied experimentally (or numerically) by probing particles of complex shapes with radiation of various frequencies, i.e. by using a "trial-and-error" approach.
In the talk, a direct approach to the analysis of resonance frequencies, plasmon resonance modes and to the study of unique physical features of plasmon resonances will be presented. The central idea of this approach is to treat plasmon resonances as an eigenvalue problem for specific boundary integral equations. This approach reveals the unique physical property of plasmon resonances: resonance frequencies depend on particle shapes, but they are scale invariant with respect to particle dimensions, provided that they remain appreciably smaller than the free-space wavelength. It turns out that the integral operators in the integral equations are compact, and hence the plasmon spectrum is discrete. General properties of this spectrum, the excitation conditions for specific plasmon modes and the time-dynamics of their excitation and dephasing will be discussed. Plasmon resonances in semiconductor nanoparticles will be briefly reviewed as well. These resonances are of special interest because they can be controlled through optical manipulation of carrier densities. This optical controllability is promising for the development of nanoscale light switches and all-optical nano-transistors. Interesting connections between plasmon resonances and the Riemann hypothesis will be briefly outlined as well.
BIO: Prof. Mayergoyz received his Master and Ph.D. degrees in the former Soviet Union where he worked as a senior research scientist in the Institute of Cybernetics of Ukranian Academy of Sciences before his emigration to the United States. On his arrival to the United States in 1980, he became a full professor of Electrical and Computer Engineering Department of University of Maryland, College Park. For many years, he served as a consultant for the Research and Development Center of General Electric Company and has been selected as a visiting research fellow of this center. He has authored and coauthored ten books and over 300 scientific papers. He is a Fellow of IEEE (1988), Visiting Research Fellow of GE Research and Development Center (1988), Distinguished Lecturer of the IEEE Magnetics Society (1994), Distinguished Scholar-Teacher of University of Maryland, College Park (1994) and a recipient of Outstanding Teacher Award of College of Engineering (1987).
Faculty Host: Reza Ghodssi
This Event is For: Public • Clark School