Seminars and Colloquia, January through June, 2008

• This Week's schedule.
• Earlier Semesters.
• Typical Week's schedule.
• January 1-4, 2008's schedule.
• January 7-11, 2008's schedule.
• January 14-18, 2008's schedule.
• January 21-25, 2008's schedule.
• January 28-February 1, 2008's schedule.
• February 4-8, 2008's schedule.
• February 11-15, 2008's schedule.
• February 18-22, 2008's schedule.
• February 25-29, 2008's schedule.
• March 3-7, 2008's schedule.
• March 10-14, 2008's schedule.
• March 17-21, 2008's schedule.
• March 24-28, 2008's schedule.
• March 31-April 4, 2008's schedule.
• April 7-11, 2008's schedule.
• April 14-18, 2008's schedule.
• April 21-25, 2008's schedule.
• April 28-May 2, 2008's schedule.
• May 5-9, 2008's schedule.
• May 12-16, 2008's schedule.
• May 19-23, 2008's schedule.
• May 26-30, 2008's schedule.
• June 2-6, 2008's schedule.
• June 9-13, 2008's schedule.
• June 16-20, 2008's schedule.
• June 23-27, 2008's schedule.

Seminars and Colloquia, Typical Week:

Physics Undergraduate Journal Club:

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

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

Oklahoma State Physics Department

Seminars and Colloquia, January 1-4, 2008

No talks scheduled: Prelim Exams

Oklahoma State Physics Department

Seminars and Colloquia, January 7-11, 2008

First Week of Classes

Oklahoma State Physics Department

Seminars and Colloquia, January 14-18, 2008

Second Week of Classes

Oklahoma State Physics Department

Seminars and Colloquia, January 21-25, 2008

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

Solid freeform fabrication (SFF) was introduced to rapidly assemble engineering prototypes for form and fit. Direct write approaches to SFF offer the additional advantage of being able to vary composition within a three-dimensional structure. Our group has been working to develop this capability in a colloidal gel based SFF technique to assemble ceramic/ceramic and ceramic/metal composites. This presentation will highlight our recent results in printing ternary arrays of barium titanate, barium zirconate and strontium titanate as a combinatorial approach to probing electrical properties of ceramics. In addition, our work to engineer residual stresses in alumina-zirconia composites via the thermal expansion mismatch will be discussed. X-Ray tomography and in-situ X-ray stress analysis were used to quantify residual stress and structural inhomogeneities in these structures. Finally, our preliminary work on printing three dimensional metal ceramic composites will be showcased.

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 28--February 1, 2008

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

Is the Higgs boson the last undiscovered Standard Model particle? Or, is it going to be one of the first new particles that point to a more general theory of the deepest structure of matter? Then again, may be there is no Higgs boson to begin with… These questions have a prominent role in shaping the research programs at the energy frontier of particle physics. The CDF Collaboration at the Fermilab Tevatron has developed a comprehensive program targeted at finding evidence for the elusive Higgs boson(s).  I will present a review of what we have learned so far, how we got there, and what we hope to achieve by the end of the Tevatron program at Fermilab.

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 4-8, 2008

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

The Higgs particle is the last missing piece of the Standard Model of particles and fields. Its discovery may shed light on the fundamental question of the origin of mass. I will explain why the high energy physics experimentalists are so excited about searching for Higgs, how we do it in the D0 experiment at the Tevatron collider at Fermilab, and what is the current status and perspectives of the Higgs search.

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 Condensed Matter Physics and Optics (Informal):

Abstract:

We discuss light scattering off Cooper-paired Fermi atoms both at zero and finite temperatures. We derive the response function for stimulated light scattering. Polarization of light has been shown to play an important role in the excitation of quasiparticles and the Bogoliubov-Anderson phonon. We also analyze finite temperature effects on the excitation spectrum.

Oklahoma State Physics Department

Seminars and Colloquia, February 11-15, 2008

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

One of the most fundamental challenges facing particle physics and cosmology is the abundance of matter in the universe—where antimatter is present only in minuscule quantities.  First observed in 1964 in rare decays of long-lived neutral kaons, violation of the combined charge parity (CP) can be shown to have been a key property of the laws of physics that governed the Early Universe, a necessary condition for the formation of macroscopic quantities of baryonic matter: stars, planets, and eventually life.  CP violation is thus one of the most intriguing physics phenomena—and one of the most intensely studied.

A brief historical and theoretical introduction to CP violation and its significance to cosmology will be followed by a review of the experimental techniques employed at B-meson factories to make precise measurements of CP-violating quantities and to search for signs of physics beyond the Standard Model.  We will review the measurements performed by the BaBar and Belle experiments where CP violation has been firmly established, and discuss how recent advances in harnessing the full particle-identification power of the BaBar detector have helped pave the way to the observation of CP violation in the time distribution of B⁰ → π⁺π⁻ decays and in the charge asymmetry of the B⁰ → K⁺π⁻ decays.  In conclusion, we will recap the current experimental status of CP violation and the Standard Model, and take a glimpse at their 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.

Informal Chalk & Board Seminar:

Oklahoma State Physics Department

Seminars and Colloquia, February 18-22, 2008

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Postponed till next day due to late arrival of speaker.

Physics Colloquium:

Abstract:

Structural information on nanometer-sized gold particles has been limited, due in part to the problem of preparing homogeneous material.  The synthesis, crystallization and x-ray structure determination of a p-mercaptobenzoic acid (p-MBA)–protected gold nanoparticle, which comprises 102 gold atoms and 44 p-MBAs will be presented.  The central gold atoms are packed in a Marks decahedron, surrounded by additional layers of gold atoms in unanticipated geometries.  The p-MBAs interact not only with the gold but also with one another, forming a rigid surface layer.  The particles are chiral, with the two enantiomers alternating in the crystal lattice.  The discrete nature of the particle may be explained by the closing of a 58-electron shell.  Applications for Au102 and similar particles include their use as vectors for multivalent display and delivery of small molecule drugs, and use as selection and alignment markers for biological electron microscopy.

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:

Oklahoma State Physics Department

Seminars and Colloquia, February 25-29, 2008

Physics Colloquium:

Abstract:

Solid-state nuclear magnetic resonance (SSNMR) is a versatile and powerful non-invasive method for problems of significance in biological physics, condensed matter physics, and chemistry. Physiopathologically important membrane proteins and high-molecular-weight protein aggregates are difficult to study by conventional structural methods such as X-ray crystallography and solution NMR due to the long-range order requirement and particle size limitation, respectively, but are generally accessible to SSNMR. Recent advances that dramatically boost experimental sensitivity and measurable inter-nuclei distances serve as a new paradigm in the field of biomolecular SSNMR. Such advances have also opened up new opportunities for pharmaceutical research.

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:

Lipid membranes are an essential building block of all cellular life, separating the inside of a cell from the outside and compartmentalizing the cell interior. Once thought of as passive and featureless environments for membrane proteins, a new picture of bio-membranes has begun to emerge that paints them as structured, complex fluids that are organized on many time and length scales. Recent advances in optical microscopy and spectroscopy techniques have facilitated the study, on a single molecule level, of membrane structure, membrane interactions with proteins and their underlying physics. New results on both bio-mimetic model membranes and live cell membranes not only gives credence to the new membrane model, but also point towards a much more active role for membranes in the fascinating physicochemical machinery of cellular life.

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 3-7, 2008

Physics Colloquium:

Abstract:

Encoding qubits in single photons has usually relied on discrete degrees of freedom such as polarization. The continuous spatial degree of freedom of single photons, on the other hand, has been the domain of “quantum imaging” and not of information processing. In this talk I present a novel embodiment of a photonic qubit that makes use of one continuous spatial degree of freedom of a single photon and relies on the parity of the photon’s transverse spatial distribution and is thus a fusion of these two distinct research endeavors. Experimental arrangements are identified and constructed comprising simple optical components, without nonlinearities or moving parts that implement operators in the spatial-parity space of single-photon fields. Using optical spontaneous parametric down-conversion to produce photon pairs, the controlled generation of entangled-photon states in this new space is demonstrated. Specifically, two Bell states, and a continuum of their superpositions, are generated by simple manipulation of a classical parameter, the optical-pump spatial parity, and not by manipulation of the entangled photons themselves. Using this physical realization, the first experimental violation of Bell's inequality in the spatial domain using the Einstein-Podolsky-Rosen state is demonstrated. I will also describe future developments of this work that rely on using two spatial dimensions per photon and the interplay between the polarization of a photon and its transverse spatial parity. This allows encoding three qubits per photon, thus enabling the manipulation of a set of sophisticated cluster states useful for one-way quantum computation in simple optical arrangements, and could be used as a foundation for future experiments in quantum information 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.

Special Physics Colloquium:

Abstract:

Small transition metal clusters supported on metal oxides and in zeolite cages represent an important class of catalysts. The structure of some systems was characterized by EXAFS. Unusually long metal-metal distances motivated us to carry out extensive computational studies. We even developed a suitable QM/MM approach, covEPE, by extending the elastic polarizable environment strategy to covalent-polar materials. Our computational studies on zeolite-supported Rh₆, for the first time, provided convincing evidence that such clusters, when produced via a chemical route, preferentially exist as hydrides. Small clusters of late transition metals in general were predicted to exhibit a propensity for the hydride form when supported in zeolite cages. Very recently, we revisited the problem of metal-metal distances in zeolite-supported Ir₄, which originally had started our interest in this field.

Please note the earlier than normal starting time and different room for this colloquium.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

While a typical galaxy like the Milky Way experiences one supernova event every century, these exceptionally rare occurrences are responsible for a significant fraction of the heavy elements which are found throughout the Universe and which are the building blocks of planets like the Earth. Further, the progenitor stars have very short life spans and they are usually obscured by the gas and dust distributed throughout our galaxy’s disk and regions of ionized surrounding the star. So we must look to other galaxies to study these objects. However, our optical search is hampered by the large distances to these galaxies and the uncertainty as to which stars out of 100s of billions to focus our efforts.

Fortunately, with radio telescopes like the Very Large Array we can discern the pre-explosion, evolution of supernova progenitor stars after they have exploded and with every year of radio monitoring yielding roughly 1,000 yrs of pre-explosion evolution. I will present the results of almost 30 years of radio monitoring of supernovae, highlighting what we have learned about the evolution of the stars that eventually become these important and enigmatic events.

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 Condensed Matter Physics and Optics (Informal):

Oklahoma State Physics Department

Seminars and Colloquia, March 10-14, 2008

APS March Meeting

Oklahoma State Physics Department

Seminars and Colloquia, March 17-21, 2008

Spring Break

Oklahoma State Physics Department

Seminars and Colloquia, March 24-28, 2008

No talks scheduled at this time.

Oklahoma State Physics Department

Seminars and Colloquia, March 31-April 4, 2008

Physics Colloquium:

Abstract:

The cause for the observed acceleration in the expansion of the universe is unknown, and dubbed “dark energy” for convenience. Dark energy could be an unknown energy component, or a modification of Einstein’s general relativity. I will examine the most promising methods for probing dark energy, and discuss recent results and future prospects.

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 7-11, 2008

Physics Colloquium:

Abstract:

In this talk, I will discuss applications of quantum mechanics in semiconductor heterostructures and devices based on three research subjects that I have worked on.  The three subjects are mid-IR interband cascade lasers, bipolar cascade lasers with quantum well (QW) tunnel junctions, quantum real space transfer.  Their current statuses will be presented to reflect different stages of research and development.

Interband cascade (IC) lasers represent a relatively new class of mid-IR semiconductor diode lasers.  Using interband tunneling facilitated by broken band-gap alignment in type-II QWs, IC lasers reuse each injected electron in cascade sages for multiple photon emission with high quantum efficiency.  Since the proposal in 1994, IC lasers have been developed from concept to efficient devices with practical applications in chemical sensing and many others to come.

Bipolar cascade lasers with QW tunnel junctions have been demonstrated at emission wavelength near 2 microns with the initial success in proof-of-concept.  In principle, they may be able to produce high output powers with narrow line-width, but their performance is still far behind the expectation.

Quantum real-space transfer of carriers in semiconductor heterostructures is a proposal for the realization of a novel functionality, which relies solely on the wave nature of electrons governed by quantum mechanics.  Issues associated with realistic scattering are identified for unambiguously demonstrating the quantum real-space transfer in practical situations.  Specific QW structures for realizing the quantum real-space transfer are proposed with calculations for practical assessment.

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.

Biophysics Seminars:

Abstract:

Different experimental techniques for time-resolved structural studies of proteins will be reported. The first talk employs nanosecond temperature jump to trigger protein folding and unfolding using intense infrared laser pulses, and perform time-resolved infrared spectroscopy to probe protein dynamical structures. The second talk will report two-color subpicosecond mid-infrared laser technology being developed for time-resolved structural determination of proteins in analogy with 2D NMR spectroscopy but with excellent time resolution.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 1.30 PM. Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, April 14-18, 2008

Physics Colloquium:

Abstract:

Advances in technology have made it possible to fabricate structures like dots, and wires on the micro- and nano-meter scale. Such quantum dots can act as artificial atoms, with spectra and shell structure similar to those of real atoms. Recently it has also become possible to fabricate arrays of rings, each only tens of nanometers across. If a quantum dot can be thought of as an artificial atom, then rings (and other more complicated structures) can be thought of as “atoms” that do not exist in nature. We can vary their geometry to control properties such as polarizability, and coupling strength in order to produce new types of correlated systems.

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 21-25, 2008

Prefinals Week

College of Engineering, Architecture and Technology—Southwest Mechanics Lecture Series:

Abstract:

This talk will describe a method for seamless integration of orbital-free density functional theory calculations with continuum mechanics. Density functional theory, a formulation of quantum mechanics, has provided insights into various material properties in the recent decade. However, the computational complexity of this approach has made other aspects, especially those involving defects, beyond reach. We describe a method that enables the study of a multi-million atom cluster using orbital free density functional theory with no spurious physics or restrictions on geometry. The key idea is a systematic means of adaptive coarse-graining retaining full resolution where it is necessary and coarsening with no patches, assumptions or structure. We demonstrate the method, its accuracy under modest computational cost, and the physical insights it offers using various examples motivated by the radiative damage of structural materials.

Biographical sketch: Kaushik Bhattacharya is Professor of Mechanics and Materials Science and Executive Officer for Mechanical Engineering at the California Institute of Technology. He received a B.Tech degree in Mechanical Engineering from the Indian Institute of Technology, Madras, a Ph.D in Mechanics from the University of Minnesota, and post-doctoral training at the Courant Institute. His research concerns the mechanical behavior of solids, and specifically uses theory to guide the development of new materials. He has authored over 75 peer-reviewed scientific articles and a book on shape-memory materials. He has supervised 13 doctoral students and 9 postdoctoral scholars. He has held visiting positions at Cornell University, Heriot-Watt University, Max-Planck-Institute, Cambridge University, the Indian Institute of Science, and the Jet Propulsion Laboratory. Bhattacharya is an Editor of the Journal of the Mechanics and Physics of Solids and serves on other editorial boards. Among the international meetings he has organized was a four-month program on Mechanics at the Isaac Newton Institute, Cambridge, England in 1999. He has received an NSF Young Investigator Award, the Charles Lee Powell Award, the Society of Engineering Science Young Investigator Prize, the ASME Special Achievements Award in Applied Mechanics, and, in 2005, the ASME Best Paper Award in the area of Active Materials.

Further Information: (405) 744-5900 and http://www.mae.okstate.edu/

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Oklahoma State Physics Department

Seminars and Colloquia, April 28-May 2, 2008

Finals Week

Oklahoma State Physics Department

Seminars and Colloquia, May 5-9, 2008

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

Oklahoma State Physics Department

Seminars and Colloquia, May 12-16, 2008

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, May 19-23, 2008

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, May 26-30, 2008

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 2-6, 2008

Oklahoma State Physics Department

Seminars and Colloquia, June 9-13, 2008

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 16-20, 2008

Oklahoma State Physics Department

Seminars and Colloquia, June 23-27, 2008

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