This page lists all of the abstracts for the Fall 2011 colloquium series. For dates and speakers, see Colloquium Fall 2011.
"Summer undergraduate research Colloquium", department colloquium August 26, 2011
Cinthia Padilla, Alex Gauf, Amos Jo, Bobby Wright, Gaby Serna and Fabian Magana-Sandoval, CSUF Physics
Over the summer break a number of students in the Physics Department, both at the undergraduate and Masters level, had the opportunity to undertake research projects in some of the Department’s research laboratories. The students worked on projects either concerned with gravitational wave detection or electron collisions. In a highly successful summer in both groups, some of the students data has already been submitted for publication and presented at international conferences. In this seminar, 6 undergraduate students will present and discuss the results from their research.
"Vortices in the electron-pair continuum, or just deep bubbles in my Guinness," department colloquium Sept 2, 2011
Jim Feagin, CSUF Physics
Freshly pulled and consumed, a finely foaming pint of Guinness is found to greatly facilitate contemplation of certain deep minima (singularities) observed in the (e, 2e) scattering continuum. We will describe our interpretation of the kinematics of such minima in terms of possible vortices in the electron-pair continuum by quantizing rotations of the momentum plane of the electron pair about the pair's relative momentum through the singularity. Mention will also be made of a recent symposium in Dublin we participated in, and the ample opportunity offered there to sample Guinness and deliberate the origins of vortices in the excellent Irish versions of the beer.
"Astrobiology of Icy Worlds: Photochemistry of Planetary Ices," department colloquium Oct 14, 2011
Dr. Paul V. Johnson, Senior Scientist, The Jet Propulsion Laboratory, California Institute of Technology
The icy worlds of the outer Solar System are of significant astrobiological interest due, in large part, to the evidence of liquid water beneath the surfaces of a number of Jovian and Saturnian satellites. The surfaces of these bodies are irradiated by solar photons as well as energetic solar wind and planetary magnetosphere protons and electrons. These energy sources can impact/penetrate the surface and can contribute to the chemistry of the surface material. If compounds of biological origin are present in the surface ice layer, can they be detected as evidence of biological activity, or do they decompose too rapidly in the surface radiation environment? A review of recent amino acid photolysis studies addressing this question will be presented.
"Ultrafast Spin Dynamics Solids: "Femtomagnetism and Spintronics""
Dr. Hans Christian Schneider, Professor, Physics Department and Research Center OPTIMAS, University of Kaiserslautern, Germany
The electron spin has been exploited extensively in magneto-electronic devices, such as hard disks. Device designs have approached the nanoscale, but the switching times have not quite followed suit, and
are still much longer than what is available in state-of-the-art laser labs. Consequently, there is a huge interest to understand spin dynamics in solids (ferromagnets, metals, semiconductors) at ultrashort timescales, especially femtosecond opto-magnetism. I will present some recent experimental results in the field of femtosecond laser-induced spin-dynamics in semiconductors and ferromagnets. I will also discuss some of the theoretical concepts
used in the description of these phenomena.
"Beyond Traditional Quantum Measurement: A Game of Quantum Peek-a-Boo with a Purpose"
Kyle Keane, Department of Physics and Astronomy, University of California, Riverside
What we learn about measurement in quantum mechanics from textbooks is not the complete story. The full irreversible collapse of the wavefunction is not the only possible outcome from the observation of a quantum system. We will discuss the other possibility, when the wavefunction is only partially collapsed by what is called a “weak measurement.” Within this new framework we discover that it is even possible to undo these measurements and return a quantum system to its original superposition. These measurements can also be used to suppress the unwanted evolution of a quantum system due to interactions with its environment. We will discuss the theoretical application of “weak measurements” for decoherence suppression, and a recent experimental demonstration of its effectiveness.
Kyle is a graduate of California State University, Fullerton and is completing his PhD at UC-Riverside.
"From multi-wavelength to multi-spectrum astronomy"
Marica Branchesi, Postdoctoral Fellow, DiSBeF - Università 'Carlo Bo' di Urbino
"Low Energy Positron Collisions with Atoms and Molec"
James Sullivan, Australian National University
A summary of recent work at ANU on low energy positron scattering on methane and other polyatomic molecules as well as earlier work on fundamental atoms will be presented.