2012 - 2013 Academic Year Colloquium Series
April 26, 2013
Dr. Nader Engheta, H. Nedwill Ramsey Professor, University of Pennsylvania
Metamaterials and plasmonic optics have become exciting platforms for controlling and harnessing light and electrons in unprecedented ways. As these fields reach a certain level of development, new directions and novel vistas are appearing in the horizon. Balancing the simplicity with the complexity in metamaterials becomes one of the key issues, and consequently modularization, functionalization, and parameterization of metamaterials may be exploited for new functionalities and possibilities in such interesting platforms that may include nonlinearity, anisotropy, chirality, non-reciprocity, and non-locality. The new paradigm of “meta-optics” offers new and transformative grounds for innovation in the field of nanooptics, nanoelectronics, and electrodynamics. I will give an overview of some of our most recent results in this area and will forecast some future possibilities.
April 19, 2013
"Overview of the Theory of Materials: Adventures in Alphabet Soup"
Dr. Joseph Schick, Department of Physics, Villanova University
Materials have been long a focus of intense research in physics, chemistry, and engineering for practical applications. In a general sense, the description of the behavior of matter can be completely obtained through application of quantum theory. In practice, however, the problem becomes quickly intractable. In this presentation I provide an overview of basic concepts of the physics of solid materials and some theoretical tools currently used to model these materials, such as density functional theory (DFT). I will illustrate the effectiveness of theoretical approximations used through comparison of some theoretically calculated and experimentally measured properties for selected materials.
February 1, 2013
"Adventures in Frustrated Magnetism"
Dr. Jeremy Carlo, Department of Physics, Villanova University
In recent years the topic of frustrated magnetism has attracted significant interest. Magnetic frustration occurs when the geometric arrangement of ions prevents magnetic order, such as ferromagnetism or antiferromagnetism, from arising. Frustrated materials are known for a wide variety of ground states and the accessibility of subtle physics normally masked in ordinary magnetic materials. I will give an introduction to the topic of magnetic frustration, and an overview of some of the work my group has done and will be doing in the field. I will focus on materials exhibiting face-centered structural symmetry, including the double perovskites, which allow for systematic studies of the effects of lattice distortion, moment size, doping and spin-orbit coupling.
November 30, 2012
“Time-resolved imaging of spin dynamics in magnetic nanostructures”
Dr. Xuemei Cheng, Department of Physics, Bryn Mawr College
November 9, 2012
“On Hot Electron Transfer in Mesoscopic Semiconductor Wires and Its Remarkable Tuning”
Dr. Jonathan Spanier, Drexel University, Department of Materials Science & Engineering
Nanowires provide fascinating opportunities to study the effects of finite size, of shape anisotropy, and of surface chemical environment on the phase stability in ferroic materials and on optical properties and electronic transport within semiconductors. Moreover the integrating of different functional materials within individual nanostructures permits investigation of physical and functional properties where interfaces and surfaces play pivotal roles.
I shall first present on our recent work in the proximal probe-based analyses and model calculation results involving ferroelectric polarizations within individual oxide nanowires, and within perovskite nanoshells surrounding selected other materials, including magnetoelastic coupling. In the second part of my talk I shall discuss our recent work involving the electronic and optoelectronic transport within core-shell radial semiconductor heterojunction nanowires, including ultrafast response and several modes of tuning hot electron transfer across co-axial interfaces. I will discuss implications of these results for optoelectronic devices: dynamic manipulation of this transfer rate permits the introduction and control of a continuously adjustable phase delay over a wide range within a single nanometer-scale device element.
October 26, 2012
“Abraham, Lorentz, Fermi & Gauss: Energy and Momentum in Classical Electrodynamics”
Dr. Robert Jantzen, Villanova University, Mathematics
September 28, 2012
“ The Age of Precision Cosmology"
Dr. David T. Chuss, Villanova Alumnus, NASA Goddard Space Flight Center