Seminars and Colloquia, July through December, 2009

• This Week's schedule.
• Earlier Semesters.
• Typical Week's schedule.
• July 6-10, 2009's schedule.
• July 13-17, 2009's schedule.
• July 20-24, 2009's schedule.
• July 27-31, 2009's schedule.
• August 3-7, 2009's schedule.
• August 10-14, 2009's schedule.
• August 17-21, 2009's schedule.
• August 24-28, 2009's schedule.
• August 31-September 4, 2009's schedule.
• September 7-11, 2009's schedule.
• September 14-18, 2009's schedule.
• September 21-25, 2009's schedule.
• September 28 - October 2, 2009's schedule.
• October 5-9, 2009's schedule.
• October 12-16, 2009's schedule.
• October 19-23, 2009's schedule.
• October 26-30, 2009's schedule.
• November 2-6, 2009's schedule.
• November 9-13, 2009's schedule.
• November 16-20, 2009's schedule.
• November 23-27, 2009's schedule.
• November 30-December 4, 2009's schedule.
• December 7-11, 2009's schedule.
• December 14-18, 2009's schedule.
• December 21-25, 2009's schedule.
• December 28-31, 2009's schedule.

Seminars and Colloquia, Typical Week:

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

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

Oklahoma State Physics Department

Seminars and Colloquia, July 6-10, 2009

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, July 13-17, 2009

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, July 20-24, 2009

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, July 27-31, 2009

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, August 3-7, 2009

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, August 10-14, 2009

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, August 17-21, 2009

First Week of Classes

Laboratory Safety Meeting:

Abstract:

Warren Grider will be discussing laboratory safety as well as some recent developments in the area of IT security. Charles Hunt will present information on the new online Chemical Safety Assistant software that has been implemented by OSU Environmental Health and Safety. This meeting is MANDATORY for all Physics department faculty, staff, and students.

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, August 24-28, 2009

Second Week of Classes

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, August 31-September 4, 2009

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

It is now recognized that arrays of classical waveguides are suitable elements for realizing a number of condensed matter and quantum optical effects like Bloch oscillations, Anderson localization, Hong-Ou-Mandel two photon interference, electromagnetically induced transparency. Further analogs of many quantum effects can be studied in such structures as various interactions can be controlled by design. Very recently waveguides along with single photons have been shown to form basic units for quantum network architecture. This talk would focus on some of these developments.

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, September 7-11, 2009

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

Abstract:

After an introduction to the existing schemes for improving the limit of phase measurements I would describe a strategy which combines advantages of both coherent detections and detections based on entangled states of photons.

Chemistry Department Seminar:

Abstract:

Biological macromolecules offer unique well-defined chemical and biological features for developing nanotechnology and nanomedicine. They can serve as scaffolds for directing nano-synthesis and assembly, as reactors for nanomaterials growth, as building blocks in hierarchical assembly, as reagents with multivalent sites for chemical conjugation, or as tools for identifying target-recognizing biomolecules. My research group is actively employing proteins, spider silks, viruses, flagella and bacteria to perform these functions to develop nanotechnology and nanomedicine. This talk will highlight our recent work in this area and focus on the use of two genetically modifiable biomacromolecules (phage and bacterial flagella). Filamentous phage is a nanorod-like virus (∼900 nm long and ∼7 nm wide) that specifically infects bacteria and is non-toxic to human beings. It is self-assembled from proteins and DNA with proteins as a coat and DNA as a core. Because the coat protein is encoded by the DNA core, foreign peptides can be genetically fused to the coat protein, enabling the site-specific modification of surface chemistry of the phage. Bacterial flagella are protein nanotubes (with an outer diameter of ∼15 nm and tunable length) protruding from the exterior surface of bacteria. These protein nanotubes are self-assembled from thousands of protein subunits and can be genetically modified to display different peptides on the surface. We have applied both phage and flagella to direct the synthesis and assembly of nano- and biomaterials and develop anti-cancer therapeutics with cancer-targeting capabilities. Our work shows that genetically modifiable biomacromolecules are unique players in developing novel nanomaterials and nanomedicines.

Note: Refreshments at 3:00 PM in Room PS 117.

Oklahoma State Physics Department

Seminars and Colloquia, September 14-18, 2009

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Chemistry Department Seminar:

Abstract:

Self-assembly governed supramolecular construction of donor-acceptor nanostructures capable of mimicking biological functions is one of the fastest growing areas of research. The potential application of these to the design of molecular systems lies in self-replication, light energy harvesting and nanotechnology. Mimicking the primary events of the reaction centers of photosynthetic bacteria is an important area of research since it directly involves harvesting solar energy.

The present talk will focus on the design and photoinduced electron transfer reactions in supramolecular donor-acceptor nanostructures composed of ferrocene, porphyrin, fullerene and carbon nanotubes. Utilization of metal-ligand axial coordination, crown ether-ammonium cation, hydrogen bonding involving complimentary base-pairing, pi-pi interactions, and a combination of one or more of these binding approaches in the construction of the nanostructures will be discussed. Results of photoinduced charge stabilization, as applicable for light energy harvesting, in the novel supramolecular systems will be discussed. Finally, results of the photoelectrochemical cells for light energy conversion build using the supramolecular concepts will be presented.

Note: Refreshments at 3:00 PM in Room PS 117.

Oklahoma State Physics Department

Seminars and Colloquia, September 21-25, 2009

Physics Colloquium:

Abstract:

Szilard¹ made a decisive step toward solving the Maxwell demon problem by introducing and analyzing the single atom heat engine. Bennett² completed the solution by pointing out that there must be an entropy, ΔS= k ln 2, generated as the result of information erased on each cycle. Nevertheless, others have disagreed. For example, philosophers such as Popper “have found the literature surrounding Maxwell’s demon deeply problematic.”

In this talk, we will explore a new kind of single atom quantum heat engine which allows us to resolve the Maxwell demon paradox simply, and without invoking the notions of information or entropy. The energy source of the present quantum engine³ is a Stern–Gerlach apparatus acting as a demonesque heat sorter. An isothermal compressor acts as the entropy sink. In order to complete a thermodynamic cycle, an energy of ΔW= kT ln 2 must be expended. This energy is essentially a “reset” or “eraser” energy. Thus Bennett’s entropy ΔS = ΔW/T emerges as a simple consequence of the quantum thermodynamics of our heat engine. It would seem that quantum mechanics contains the kernel of information entropy at its very core. That is, the concept of information erasure as it appears in quantum mechanics⁴ and the present quantum heat engine have a deep common origin.

    * Scully, et al., Physica E 29, 29–39 (2005).

1. Szilard, Zeitschrift für Physik, 53 (1929) 840.
2. Bennett, Sci. Am. 255 (1987) 107.
3. Scully, Phys. Rev. Lett. 87 (2001) 22601.
4. Scully and Drühl, Phys. Rev. A 25 (1982) 2208.

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, September 28-October 2, 2009

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

I will present experimental data demonstrating a two-atom CNOT gate at an atomic separation of 10 microns using Rydberg state mediated interactions. We also show that the CNOT gate can be used to create two-atom entangled states. In addition to quantum gates the long range Rydberg interaction appears well suited for generating many particle entanglement, and deterministic quantum interfaces between matter and photonic qubits. I will discuss some examples of these quantum information applications.

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, October 5-9, 2009

Physics Colloquium:

Abstract:

Structures provide an important basis for us to understand the properties and functions of proteins and help applications such as drug design and bioengineering. Protein x-ray crystallography, though very useful, suffer from several accuracy problems, especially for the metal sites. Recently, we have used and developed many quantum mechanics (QM) methods, enabling high accuracy calculations of numerous NMR, ESR and Mössbauer observables with very broad experimental ranges. We also found that QM calculations of these properties are very sensitive structural probes and have successfully used them in refinement of structures for metalloproteins having different spin states, oxidation states, coordination environments, and reaction states. These properties are more accessible from experiments than those from protein x-ray crystallography, which allow us to develop applications for biosystems beyond crystalline proteins. Here, as an example, I will show that how the accurate calculations of ³¹P NMR chemical shifts helped to obtain refined structures for both drug- and substrate-binding sites in a protein-drug complex. The drug is a kind of bisphosphonates, currently used to treat bone resorption diseases. Such kind of compounds has also been found to have potent anti-cancer and anti-HIV effects. In addition, this investigation has yielded useful information in finding new drug leads. The actual protonation state of a diphosphate substrate in the protein was determined to be mono-protonated, for the first time. I will also talk about applications in human disease related peptides and protein complexes of a newly recognized signaling molecule.

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):

Abstract:

Recent experiments have shown that waveguides along with non-classical light are a logical choice for future quantum information processing tasks. Since entanglement plays a prominent role in all these applications, it is important to understand the entanglement dynamics in these structures. In this talk, we focus on the generation of entanglement and its survival in integrated waveguide structures. We study entanglement in terms of quantitative measures and examine the robustness of waveguide structures in retaining the entanglement.

Students’ Fall break, Friday, October 9

Oklahoma State Physics Department

Seminars and Colloquia, October 12-16, 2009

Physics Colloquium:

Abstract:

Proteins perform a vast array of biological functions. Some of them transport electrons, protons, ions, to macromolecules. The mechanism of electron transfer reactions in proteins is well understood, dominated by quantum tunneling. However, after decades of hard research, the physical mechanism of proton transfer remains obscure. In a proof of concept study, we employed a quantum physics method, namely density functional theory (DFT), to characterize the energy landscape of proton transfer for model systems. Based on this first principle computational study, we identified the key structural elements that control the direction and the rate of direct proton transfer from the donor to the acceptor. We will discuss that this mechanism may be generalized to proton transfer in variety of proteins and in water.

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, October 19-23, 2009

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

The first part of my talk will be on the dissipation in quantum dots (QDs). The heat generation by an electric current flowing through a quantum dot containing both electron-electron interaction and electron-phonon interaction is studied. We find that heat generation is in general qualitatively different from the current. It is non-monotonic with current and many unique and interesting behaviors emerge. The heat generation could be very large in the Coulomb blockade region, in which the current is very small due to the Coulomb blockade effect. On the other hand, in the resonant tunneling region, the heat generation is very small despite a large current, an ideal condition for device operation.

The second part of my talk will be the thermoelectric properties in quantum dots. We investigate the figure of merit of a quantum dot in the Coulomb blockade regime. It is found that the figure of merit ZT may be quite high if only single energy level in the QD is considered. On the other hand, with two or multi energy levels in the QD and without the Coulomb interaction, the ZT is strongly suppressed by the bipolar effect due to the small level spacing. However, in the presence of the Coulomb interaction, the effective level spacing is enlarged and the bipolar effect is weakened, resulting in ZT to be considerably high. Thus, it is more likely to find a high efficient thermoelectric QD with a large Coulomb interaction.

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.

Note: The dimensionless figure of merit ZT is the product of the figure of merit Z=σS²/κ and the average temperature T, where σ is the electrical conductivity, S the Seebeck coefficient (voltage per temperature difference) and κ the thermal conductivity.

Oklahoma State Physics Department

Seminars and Colloquia, October 26-30, 2009

Physics Colloquium:

Abstract:

At the heart of many state of the art sensors lies an atom interferometer. These devices have demonstrated outstanding sensitivities. However, this is not true for the field of magnetometers. In this talk, I explore the workings of an atom interferometer designed to measure magnetic fields and show that, to first order, the interferometer is NOT sensitive to magnetic fields BUT is sensitive to magnetic field gradients. This makes an atom interferometer an INHERENTLY gradient device, useful for Naval applications. I then will discuss some of the building blocks we have had to develop to construct such a device, which is underway.

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, November 2-6, 2009

Physics Colloquium:

Abstract:

Decoherence is the process by which a quantum mechanical system interacting with its natural environment loose its coherence. The absence of quantum signatures, like the superposition principle in macroscopic systems is attributed to the phenomenon of decoherence. Further, other effects like the abundance of chiral molecules in nature is also thought to be an artifact of this. In last few year with the advent of quantum information sciences the study of decoherence has become even more important. Any practical realization of quantum information protocols will require sustained entanglement among the quantum systems. Unfortunately it is known that entanglement is quite susceptible to decoherence. A lot of current research in quantum information sciences is thus motivated in finding ways of controlling, manipulating and even suppressing decoherence.

In this talk I will give an introductory overview of decoherence theory and its implication on quantum information sciences. I will show how decoherence can effect the time dependence of entanglement in two novel systems—quantum dots and photonic waveguides, which are frontrunner in implementation of quantum logic circuits. Finally I will propose a method to achieve sustained entanglement in microscopic systems by using photonic band gap materials. A substantial part of this talk is based on my ongoing Ph.D. work at Oklahoma State University.

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, November 9-13, 2009

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

Proton radiation therapy is becoming increasingly popular because it promises dose conformality comparable to or better than those in Intensity Modulated Radiation Therapy (IMRT) treatments, while significantly sparing the normal surrounding tissue because of the low entrance dose and virtually no exit dose when compared to conventional treatment methods using photon or electron radiation. This presentation provides a brief overview of proton radiation therapy. The emphasis is on the physics of clinical proton dosimetry. From the physics standpoint, some important unresolved issues in the field of clinical proton dosimetry include: 1) estimating range uncertainties; 2) modeling dose distributions; and 3) measuring linear energy transfer which relates to the relative biological effectiveness of the proton dose. Research focused on advancing the knowledge in the mentioned issues through Monte Carlo simulations and measurements of proton radiation therapy beams will be presented.

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, November 16-20, 2009

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Postponed till next semester.

Oklahoma State Physics Department

Seminars and Colloquia, November 23-27, 2009

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

Thanksgiving Break, November 26-27

Oklahoma State Physics Department

Seminars and Colloquia, November 30-December 4, 2009

Prefinals Week

Oklahoma State Physics Department

Seminars and Colloquia, December 7-11, 2009

Finals Week

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Oklahoma State Physics Department

Seminars and Colloquia, December 14-18, 2009

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, December 21-25, 2009

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, December 28-31, 2009

No talks scheduled

Last Updated: August 10, 2009

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