Seminars and Colloquia, January through June, 2006

• This Week's schedule.
• Earlier Semesters.
• Typical Week's schedule.
• January 2-6, 2006's schedule.
• January 9-13, 2006's schedule.
• January 16-20, 2006's schedule.
• January 23-27, 2006's schedule.
• January 30-February 3, 2006's schedule.
• February 6-10, 2006's schedule.
• February 13-17, 2006's schedule.
• February 20-24, 2006's schedule.
• February 27-March 3, 2006's schedule.
• March 6-10, 2006's schedule.
• March 13-17, 2006's schedule.
• March 20-24, 2006's schedule.
• March 27-31, 2006's schedule.
• April 3-7, 2006's schedule.
• April 10-14, 2006's schedule.
• April 17-21, 2006's schedule.
• April 24-28, 2006's schedule.
• May 1-5, 2006's schedule.
• May 8-12, 2006's schedule.
• May 15-19, 2006's schedule.
• May 22-26, 2006's schedule.
• May 29-June 2, 2006's schedule.
• June 5-9, 2006's schedule.
• June 12-16, 2006's schedule.
• June 19-23, 2006's schedule.
• June 26-30, 2006's schedule.

Seminars and Colloquia, Typical Week:

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Journal Club on Statistical Mechanics and Condensed Matter Physics (Informal):

Oklahoma NanoNet Informal Seminar:

Oklahoma State Physics Department

Seminars and Colloquia, January 2-6, 2006

No talks scheduled: Prelim Exams

Oklahoma State Physics Department

Seminars and Colloquia, January 9-13, 2006

First Week of Classes

Special Quantum Physics Seminar:

Abstract:

Entanglement is the potential of quantum states to exhibit correlations that cannot be accounted for classically. For many reasons, it is interesting to quantify entanglement. We will describe the most relevant measures of this property and introduce the notion of “concurrence”.

Oklahoma State Physics Department

Seminars and Colloquia, January 16-20, 2006

Second Week of Classes

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, January 23-27, 2006

Physics Colloquium:

Abstract:

Last semester I modified the senior level Mechanics II class to be similar to Dr. Alan Cheville’s optics course in Electrical Engineering. The content was organized around four major problems which the students solved working in teams and wrote up as papers. The students reviewed the papers and wrote up reports. Student grades are determined using both individual and team scores. I will present my experience and observations of this class.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, January 30-February 3, 2006

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Abstract:

At the LHC, W and Z boson production will be used as “benchmark” processes to calibrate various searches for the Higgs boson, SUSY, and other “new physics” processes. In the context of the PDF global analysis, we examine current data from HERA, Tevatron, and fixed-targets to properly quantify the PDF uncertainties. This helps us distinguish “new physics” from “old physics,” and thereby maximize the discovery potential of the LHC.

Oklahoma State Physics Department

Seminars and Colloquia, February 6-10, 2006

Physics Colloquium:

Abstract:

An important component of high-speed optical communication networks is a switch capable of redirecting pulses of light, where an incoming “switching” beam redirects other beams via light-by-light scattering in a nonlinear optical material. For quantum information networks, it is important to develop optical switches that are actuated by a single photon. Unfortunately, the nonlinear optical interaction strength of most materials is so small that achieving single-photon switching is exceedingly difficult. This problem appears to be solved through modern quantum-interference methods, where the nonlinear interaction strength can be increased by many orders-of-magnitude. Another desirable property of all-optical switches is that the output beams are controlled by a weaker switching beam so they can be used as cascaded classical or quantum computational elements. Current switches, however, tend to control a weak beam with a strong one.

I will describe our recent discovery of an all-optical switch that combines the extreme sensitivity of instability-generated transverse optical patterns to tiny perturbations with quantum interference methods. A transverse optical pattern is the spatial structure of the electromagnetic field in the plane perpendicular to the propagation direction. We control such a pattern with a beam whose power is up to 6,500 times weaker than the power contained in the pattern itself, verifying that the switch is cascadable. Also, the switch is actuated with as few as 2,700 photons and thus operates in the low-light-level regime. A low value of the measured switching energy density suggests that the switch might operate at the single-photon level with system optimization. More information on this project can be found at: http://www.phy.duke.edu/research/photon/qelectron/.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, February 13-17, 2006

Note: We have two colloquia next week.

Oklahoma State Physics Department

Seminars and Colloquia, February 20-24, 2006

OSU Research Week

Physics Colloquium:

Abstract:

The critical analysis of electron accelerators for radiation technologies shows that pulsed high current electron accelerator can be consider as an accelerator with high efficiency. The physical principles of pulsed low energy (100-400 keV) high current electron accelerators for radiation physics and technologies are considered in the presentation. The novel X-ray target is discussed. The analysis of compact irradiators for different industrial and scientific application is given.

The question of computer modeling for absorbed electron beam dose is presented by demonstration of software on PC.

The novel concept for real-time dose monitoring of electrons from accelerators and photons from Isotope sources are discussed. The real-time electron beam dose measurement and monitoring system for all types of accelerators is given in the report.

The scientific and industrial applications for radiation technologies discussed. The special topic of radiation technologies is adiabatic radiation technology. This type of radiation technology is discussed for broad applications (semiconductors, nanomaterials and etc.).

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Special Physics Seminar:

Abstract:

We investigate the non-classical features in the radiation of a collection of trapped atoms. In case of two atoms and considering the first-order correlation function this problem is in many respects similar to Young’s well-known classical double slit experiment. By contrast, the second-order correlation function of the fluorescence light shows a spatial interference pattern not present in a classical treatment. An outcome of this phenomenon is that bunched and anti-bunched light is emitted in different spatial directions. Moreover, if the two atoms are separated by less than a wavelength the spontaneous decay becomes spatially modulated, i.e. photons are emitted by the system at different rates depending on where the photons are recorded. In case of a chain of atoms, the spatial interference pattern of higher order correlations of the fluorescence light can be used to solve efficiently different problems in classical and quantum optics. In the first case the correlations can be used to beat the diffraction limit in lithography and microscopy. In the second case the non-classical light can be fruitfully employed in certain quantum algorithms, like Grover’s search algorithm.

Physics Colloquium:

Abstract:

Research performed over the past several years has demonstrated new methods for controlling the velocity of propagation of pulses of light through material systems. Ultra slow velocities (tens of meters per second) and ultra fast velocities (including negative velocities) have been demonstrated. This talk will commence with an overview of this field and will include a discussion of some new ideas for applications of fast and slow light based on the use of room temperature solids. This talk will also include a brief introduction to the field on quantum imaging. Image formation making use of quantum states of light allow dramatic new possibilities in the field of image science. In this contribution, we review some of the conceptual possibilities afforded by quantum imaging and describe some recent work that displays some of these features.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, February 27-March 3, 2006

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

We find that in order to completely describe the spin transport, apart from spin current (or linear spin current), one has to introduce the angular spin current. The two spin currents respectively describe the translational and rotational motion of a spin. Both spin current densities appear naturally in the spin continuity equation. Moreover we predict that the angular spin current, just like the linear spin current, can also induce an electric field.

In the second topic, the spin-orbit coupling systems with a zero magnetic field is studied under the equilibrium situation, i.e., without a voltage bias. A persistent spin current is predicted to exist under most circumstances, although the persistent charge current and the spin accumulation are identically zero. In particular, a two-dimensional quantum wire is investigated in detail. Surprisingly, a persistent spin current is found to flow along the confined direction, due to the spin precession in accompany with the particle motion. This provides an interesting example of constant spin flowing without inducing a spin accumulation, contrary to common intuition.

Note: The work is in collaboration with Q.F. Sun of the Institute of Physics, Chinese Academy of Sciences.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, March 6-10, 2006

Physics Colloquium:

Abstract:

CR-39 plastic nuclear track detector (PNTD) is a passive radiation detector that has found wide spread application in radiation dosimetry and is also used in both nuclear physics and cosmic ray experiments. Our laboratory uses CR-39 PNTD in conjunction with thermoluminescent detector (TLD) or optically stimulated luminescent detector (OSLD) to measure total dose and dose equivalent aboard spacecraft, high altitude aircraft and balloons, and commercial jetliners. We are also using CR-39 PNTD in experiments at particle accelerators to characterize the shielding properties of new materials as a function of composition and thickness for possible use as radiation shielding in future spacecraft.

Among other projects, our laboratory is currently studying the nuclear interactions produced by high energy protons on the carbon, oxygen, and calcium nuclei in tissue and bone using CR-39 PNTD irradiated in the cancer therapy proton beam at the Loma Linda University Medical Center. This has led to the development of a powerful new technique that utilizes Atomic Force Microscopy to measure very short range (between 1 and 20 μm) secondary heavy recoil particle tracks produced in the detector by high energy proton and neutron interactions with target nuclei ranging from carbon to lead.

CR-39 PNTD is a cross-linked, thermoset polymer sensitive to charged particles of LET_∞H₂O ≥5 keV/μm. Nuclear tracks are formed in CR-39 PNTD by protons of energy ≤10 MeV, α-particles ≤100 MeV, and heavy ions at all energies. Low energy neutrons are detected via tracks from recoil protons. High energy neutrons and protons can be detected via secondary particle tracks produced in nuclear interactions with the carbon and oxygen nuclei in the detector.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Journal Club on Statistical Mechanics and Condensed Matter Physics (Informal):

A few short talks will be presented in preparation for next week's APS meeting:

Oklahoma State Physics Department

Seminars and Colloquia, March 13-17, 2006

Spring Break

APS March Meeting

Oklahoma State Physics Department

Seminars and Colloquia, March 20-24, 2006

High Energy Physics Seminar:

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

We do not know 96% of the total matter in the universe at present. In this talk, a cosmological model is proposed in which Dark Energy (DE) is identified as Bose–Einstein Condensation (BEC) of some boson field. Global cosmic acceleration caused by this BEC and multiple rapid collapses of BEC into black holes etc. are examined based on the relativistic version of the Gross–Pitaevskii equation. We propose (a) a novel mechanism of inflation free from the slow-rolling condition, (b) a natural solution for the cosmic coincidence (‘Why Now?’) problem through the transition from DE into DM (Dark Matter), (c) very early formation of highly non-linear objects such as black holes, which might trigger the first light as a form of quasars, and (d) log-z periodicity in the subsequent BEC collapsing time. All of these are based on the steady slow BEC process.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Journal Club on Statistical Mechanics, Condensed Matter Physics and Optics (Informal):

Oklahoma State Physics Department

Seminars and Colloquia, March 27-31, 2006

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

The idea of symmetry between fermions and bosons (supersymmetry) in nature has allowed the particle theory models to explain a wide range of physical phenomena. A key attempt has been the explanation of the recent measurement of the dark matter content of the universe. In this talk, I will discuss the special attributes of an elegant supersymmetry model based on gauge coupling unification and mass unification that attempt to explain current physical data. However, to confirm these explanations, the supersymmetry particles are needed to be directly produced at the colliders. I will discuss the possibility of discovering the special features of the supersymmetry model at the colliders (e.g. Linear Collider and Large Hadron Collider) in order to establish the connection between dark matter and the particle physics model.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Physics Colloquium:

Abstract:

Ion implantation and ion beam analysis are powerful tools for characterization and modification of materials by means of bombarding solids with energetic ions. Although the techniques have been highly developed during the past half century, they face new challenges as material processing approaches the nanometer scales. This talk will present recent achievements in overcoming technology barriers of ion implantation in microelectronic processing. Particularly, the novel techniques of defect engineering and strain engineering for ultrashallow junction formation (<10 nm) and ultrathin layer transfer (<20 nm) for the fabrication of next generation silicon-based microelectronic devices will be discussed. Also discussed will be the recent developments in Rutherford backscattering and elastic recoil detection analysis for more precise determination of lattice location of impurities and radiation damage in crystalline solids. Examples presented in the talk cover ion-solid interactions with ion energies in the range from a few hundred eV to a few MeV. This talk will give an overview of the status and perspective of several cutting-edge techniques in ion beam processing.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, April 3-7, 2006

Chemistry Department Seminar:

Abstract:

Using a new sacrificial seeding/templating method, bulk quantities of nanospheres/fibers/tubes of all major classes of conducting polymers can be synthesized rapidly, and in essentially one step. The method isgeneral and can be extended beyond conducting polymers (polyaniline, polypyrrole and polythiophene, etc.) to any polymer that can be synthesized by precipitation polymerization. Noble metal nanoparticles spontaneously deposit on the surface of nanospheres/fibers/tubes from the corresponding metal ions in solution, yielding polymer/metal composites having a wide range of applications. Microwave heating converts the conducting polymers and polymer/metal composites to the corresponding nanocarbons in one step, i.e., carbon nanofibers, nanotubes and carbon/metal composites are obtained in which the parent morphology of the conducting polymer is retained.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

An exploratory set of studies was conducted to compare the effectiveness of the Hypothesis-Based Learning (HBL) and Physics by Inquiry (PBI) pedagogies. During the Fall 2003 and Spring 2004 semesters, 83 Oklahoma State University elementary education students received identical content instruction differing only in pedagogy. Students were assessed regarding self-efficacy, physics expectations, and physics content.

Analyses reveal that HBL and PBI cause statistically similar gains in elementary education students’ self-efficacy scores and physics expectations. Both populations were similar before and after instruction, with similar changes in performance occurring on the same items. Content assessments reveal student content mastery was similar despite different instructional pedagogies. Students scored similarly in all content areas excepting electric circuit analysis, where HBL caused significant student score improvement. HBL produces largely the same results as PBI, providing evidence that open and directed inquiry pedagogies can produce equivalent outcomes.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, April 10-14, 2006

Physics Colloquium:

Abstract:

Nonequilibrium molecular dynamics simulations were performed to study energy dissipation at the interface of sliding hydroxylated α-alumina surfaces¹ and heat transfer at the interface of diamond {111} nanosurfaces.² The velocity distribution, P(v), for the atoms in a sublayer of the sliding hydroxylated α-alumina surface is bimodal with Boltzmann and non-Boltzmann components. The non-Boltzmann, with temperatures in excess of 1000 K and as high as 2500 K, is most important for the interfacial H-atom sublayer and becomes less important in moving to a sublayer further form the sliding interface. The importance of these non-Boltzmann energy dissipation dynamics is studied as a function of the applied force and sliding velocity.

A molecular dynamics simulation was performed to study the effect of an applied force on heat transfer at the interface of model diamond {111} nanosurfaces. The force was applied to a small, hot nanosurface at 800, 1000, and 1200 K brought into contact with a larger, colder nanosurface at 300 K. Heat transfer from the hot surface occurs with exponential kinetics and a rate constant that increases linearly with the interfacial force according to 7 × 10⁻⁴ ps⁻¹/nN. This heat transfer rate is nearly independent on the temperature of the hot surface, but does change if the two nanosurfaces do not have the same H/D isotopic substitution.

1. O. A. Mazyar, H. Xie, and W. L. Hase, J. Chem. Phys. 122, 094713 (2005).
2. O. A. Mazyar and W. L. Hase, J. Phys. Chem. A 110, 526 (2006).

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

The string landscape scenario has been proposed to explain the apparent vacuum energy density of our universe which is well over a hundred orders of magnitude below the “natural” scale. In this scenario there are of order 10¹⁰⁰ potential or actual alternative universes of which at least one (ours) is suitable for the evolution of life. It is possible that, shortly after the big bang, the universe underwent a series of phase transitions in the inflationary era which culminated in our mildly accelerating universe. We propose that the ground state universe is exactly supersymmetric as in the original superstring theories and that, at some time in the future, there will be a final phase transition to this ground state universe. We discuss the prominent features of such a susy universe and attempt to estimate the most likely time of the transition.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, April 17-21, 2006

Physics Colloquium:

Abstract:

I will give a general overview of the experimental high energy physics at the Tevatron (Fermilab) and LHC (CERN) colliders. What is exciting about studying physics at colliders? What is our current understanding of the world around us? What exactly are experimentalists doing? How can 500 to 2000 people be working together in one experiment? I will discuss what brought together experimentalists in high energy physics and what we hope to discover in the nearest future.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Joint Chemistry and Physics Colloquium:

Abstract:

The electronic, structural, and chemical properties of unsupported metal and mixed-metal surfaces prepared either as single crystals or thin films have been detailed and contrasted with the corresponding properties of supported metal and mixed-metal nanoclusters [1]. The latter vary in size from a few atoms to many and have been prepared on ultrathin single crystalline oxide supports of TiO₂, Al₂O₃, and SiO₂. An array of surface techniques including reaction kinetics of carbon monoxide oxidation and vinyl acetate synthesis have been used to correlate catalytic function of these surfaces with their physical and electronic properties. Of special interest are the special physical and chemical properties that develop with metal cluster size reduction and/or metal-support interaction. Model studies of mixed-metal catalysts prepared by alloying Pd with Au will be highlighted [2].

1. M. S. Chen and D. W. Goodman, Science, 306, 252 (2004)
2. M. S. Chen, D. Kumar, C. W. Yi and D. W. Goodman, Science, 310, 291 (2005)

BIO SKETCH

Wayne Goodman joined the faculty of the Chemistry Department at Texas A&M in 1988 where is currently Distinguished Professor and the Robert A. Welch Chair. Previously he was Head of the Surface Science Division at Sandia National Laboratories. He is the recipient of the Ipatieff Award of the American Chemical Society in 1983, the Colloid and Surface Chemistry Award of the American Chemical Society in 1993, the Yarwood Medal of the British Vacuum Society in 1994, a Humboldt Research Award in 1995, a Distinguished Research Award of Texas A&M University in 1997, the Giuseppe Parravano Award in 2001, the Adamson Award for Distinguished Service in the Advancement of Surface Chemistry of the American Chemical Society in 2002 and the Gabor A. Sormorjai Award for Creative Research in Catalysis of the American Chemical Society in 2005 He is the author of over 500 publications/book chapters and is an active member/officer of a number of professional societies. He has served as an Associate Editor for the Journal of Catalysis, and currently serves on the Advisory Boards of Surface Science, Langmuir, Catalysis Letters, Topics in Catalysis, the Journal of Physics: Condensed Matter and E-Journal of Surface Science and Nanotechnology.

Note: Refreshments before talk in PS 117.

Journal Club on Statistical Mechanics and Condensed Matter Physics (Informal):

Oklahoma State Physics Department

Seminars and Colloquia, April 24-28, 2006

Prefinals Week

Physics Colloquium:

Abstract:

We present electrochemical methodology for growing crystalline metal nanowires between targeted sites in on-chip circuitry. This approach results from an innovative combination of dendritic growth and pulsed electrolysis techniques. Based on these subfields, we formulate a mechanism for the observed growth-behavior, and we test key predictions that are posed by this model. All are qualitatively borne out by experiment. The critical variable in this mechanism is the thickness of the inner diffusion layer, which characterizes the distance across which the salt concentration varies near the alternating electrode. By identifying experimental parameters that provide control over this variable, precise control over the wire-diameter and the growth velocity is attained. Significantly, this approach is amenable to growing wires composed of a wide variety of metals (such as In, Ni, Co, Pb, and Au), simply by changing the salt solution. The directed growth capability enables metallic nanowires to be grown from macroscopic electrodes to targeted sites in the interelectrode region. Progress on using this capability to interface these nanowires with specific sites on cultured muscle cells will be discussed.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3.00 PM. All students are welcome! Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, May 1-5, 2006

Finals Week

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Oklahoma State Physics Department

Seminars and Colloquia, May 8-12, 2006

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, May 15-19, 2006

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, May 22-26, 2006

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, May 29-June 2, 2006

Special Physics Seminar:

Abstract:

TBA

Oklahoma State Physics Department

Seminars and Colloquia, June 5-9, 2006

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 12-16, 2006

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 19-23, 2006

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 26-30, 2006

No talks scheduled.

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This page was prepared by Helen Au-Yang and Jacques H.H. Perk.