Seminars and Colloquia, January through June, 2015

• This Week's schedule.
• Earlier Semesters.
• Typical Week's schedule.
• January 1-2, 2015's schedule.
• January 5-9, 2015's schedule.
• January 12-16, 2015's schedule.
• January 19-23, 2015's schedule.
• January 26-30, 2015's schedule.
• February 2-6, 2015's schedule.
• February 9-13, 2015's schedule.
• February 16-20, 2015's schedule.
• February 23-27, 2015's schedule.
• March 2-6, 2015's schedule.
• March 9-13, 2015's schedule.
• March 16-20, 2015's schedule.
• March 23-27, 2015's schedule.
• March 30-April 3, 2015's schedule.
• April 6-10, 2015's schedule.
• April 13-17, 2015's schedule.
• April 20-24, 2015's schedule.
• April 27-May 1, 2015's schedule.
• May 4-8, 2015's schedule.
• May 11-15, 2015's schedule.
• May 18-22, 2015's schedule.
• May 25-29, 2015's schedule.
• June 1-5, 2015's schedule.
• June 8-12, 2015's schedule.
• June 15-19, 2015's schedule.
• June 22-26, 2015's schedule.
• June 29-July 3, 2015'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, and Optics (Informal):

Oklahoma Nanonet Informal Seminar:

Oklahoma State Physics Department

Seminars and Colloquia, January 1-2, 2015

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, January 5-9, 2015

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, January 12-16, 2015

First Week of Classes

Oklahoma State Physics Department

Seminars and Colloquia, January 19-23, 2015

Martin Luther King Day, Monday, January 19, 2014

Second Week of Classes

Oklahoma State Physics Department

Seminars and Colloquia, January 26-30, 2015

Physics Colloquium:

Abstract:

Lack of science literacy concerns all of us.  Our state senator, James Inhofe, claims global warming is a hoax.  Evolution is perennially disputed.  Students believe electricity simply comes from the wall plug, evidently by magic.  On the other hand, scientific content grows exponentially.  All become science illiterate to some degree.  So, who should address the science literacy problem? What does a science literate person need to know?

Richard Muller, a professor of physics at the University of California, accepted personal responsibility for the problem.  He developed a popular, non-mathematical, lowest level class, “Physics and Technology for Future Presidents.” He chooses physics content based on what the President of the United States needs to know.  What science is important politically?  What science is in the news?

Stephen Johnston, a physics and political science double major (2004), told me about Muller’s course.  Since Jim Harmon retired, I used Muller’s text for our Physics 1014 class last semester.  This talk will describe the students taking the class, the content presented, the homework, and the examinations.  I followed Muller’s class as closely as possible.

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 2-6, 2015

Physics Colloquium:

Abstract:

The last ten years or so has seen the development of a wide range of techniques for manipulating the matter waves associated with atoms that have a temperature of just a few hundred nano-Kelvin. In this talk, I will describe some of the experiments that my group has conducted at OSU using optical potentials for these ultra-cold atoms. These range from studies of the production of Bose–Einstein condensates using an “all-optical” process, to the use of spatially periodic potentials formed with standing light waves for quantum chaos research. I will show that the latter system is not only an important tool for examining the transition between the quantum and classical realms, but can also provide new ways to manipulate atomic matter waves for metrological 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, February 9-13, 2015

Physics Colloquium:

Abstract:

This talk will provide an overview of the popular topics of quantum computing and quantum cryptography. DOD, DOE, NASA, Amazon, Microsoft, Google are backing quantum computing, and IBM’s 3-billion research initiative includes quantum computing as a key technology. The UK recently invested nearly half a billion in an initiative in quantum technology. There already are companies in the quantum cryptography business although there are no quantum computing products. One company D-Wave claims to have a quantum computer but most researchers are not convinced that its computation is really quantum. Is QC going to change the world, or is it hype?

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 16-20, 2015

Physics Colloquium:

Abstract:

Research and development of novel and improved radiation delivery devices and methods can be prohibitively resource intensive in a clinical environment, based on the fact that accelerators are costly, beam time is sparse and patient treatments have, of course, the highest priority. Hence, performing physical experiments with radiation delivery devices may not be the most practical way of solving research problems, considering that many problems may as well be solved using a simulation environment. The Monte Carlo method provides a simulation system based on random numbers and on interaction probabilities, and is an extremely elegant and useful tool to investigate scientific problems in a virtual universe. In this presentation we will discuss development work and research of photon therapy and proton therapy related problems, using the Monte Carlo method.

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:

Optically stimulated luminescence (OSL) works on the principle that particle or photon radiation can ionize atoms within minerals. The freed electrons become trapped at light sensitive crystal defects and the number of trapped electrons increases over time. Exposure to light releases the trapped electrons and they recombine with charges of the opposite sign. The light emitted during this process is called OSL. The OSL signal is proportional to the radiation dose absorbed in the mineral and thus can be used for dosimetric purposes.

In my presentation I will explain the luminescence process and how it can be used for radiation dosimetry. I will describe an instrument for spatially resolved measurements which is suited to characterize non-uniform radiation fields. And I will describe applications of OSL ranging from environmental radiation in astrobiology, over accident dosimetry, to geologic dating.

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.

OU/OSU Condensed Matter Physics Seminar:

Abstract:

Quantum confinement in the form of zero-dimensional quantum dots (QDs) is an important scientific concept, allowing modification of quantum-mechanical properties such as energy level spacing, density of states, absorption coefficients, and so on in materials.^[1]  In this context, QDs are thought of as tailor-made “artificial atoms” in condensed matter systems.  This ability has been actively pursued in recent years to improve the performance of various photonic and optoelectronic applications.  In the case of lasers, workers have demonstrated improved coherent photon emission from QD-based lasers when the QDs were used to modify properties such as energy level spacing and the density of states of the electron transitions.  In some circumstances, these improvements have led to useful commercial products.  However, the reverse case has been less effective, such as in solar cells where photons drive electron transitions between energy levels; and the anticipated improvements in device performance due to the QDs has not yet succeeded.^[2]  In this talk, I discuss why the latter situation has arisen and then present results that explain how lattice strain management can be used to overcome some of these problems.  Specifically, the observations of lattice strain and stress behavior in QD heterostructures will be addressed, using tools such as high-resolution x-ray diffraction reciprocal space maps, atomic force microscopy, and photoluminescence to investigate and analyze strain mechanisms as found in p-i-n structures grown by molecular beam epitaxy using the Stranski-Krastanov growth method.^[3]

1. See early papers in Nanostructure Physics and Fabrication, Proceeding of International Symposium on Nanostructure Physics and Fabrication, College Station, TX (Academic Press, New York, NY, 1989) eds. M. A. Reed and W. P. Kirk.
2. C. G. Bailey, D. V. Forbes, R. P. Raffaelle, S. M. Hubbard; Near 1 V Open Circuit Voltage InAs/GaAs Quantum-dot Solar Cells, Appl. Phys. Lett. 98, 163105 (2011).
3. Jateen S. Gandhi, Choong-Un Kim, and Wiley P. Kirk, Misfit Management for Reduced Dislocation Formation in Epitaxial Quantum-Dot-Based Devices, J. Crystal Growth 364, 169–177 (2013).

Oklahoma State Physics Department

Seminars and Colloquia, February 23-27, 2015

Physics Colloquium:

Abstract:

1) Use of in-room PET for proton therapy verification — Determination of elemental tissue composition and tumor hypoxic region.

Proton therapy, now recognized as one of the most effective treatment of cancer has its great advantage since protons deposit their maximum energy just before coming to a stop. However, current CT scan (tissue electron density) based treatment plans cannot estimate the proton range very accurately. Therefore, proton therapy has a risk of not treating the cancer or damaging critical healthy tissues. In this research, two patients with head-neck cancers were treated using proton therapy and their tissue activation were imaged using an in-room PET scanner. The PET signals were deconvolved to determine the elemental tissue composition. This information can be used to calculate the proton range more accurately and also to determine the tumor hypoxic region.

2) Use of off-site PET for proton therapy verification — Development of proton activated fiducial markers for in-vivo proton therapy/range verification.

¹⁸O, ⁶³Cu and ⁶⁸Zn are strongly activated by low energy protons and decay with positron emissions. These elements were used to develop patient implantable markers which are PET/CT/US/MRI visible. They function as normal radiographic (CT) fiducial (such as gold) markers while providing proton therapy/range verification using PET.

3) Hybrid nanoparticles for radiation therapy and PET mediated molecular imaging.

Gold nanoparticles (GNP) are actively investigated as patient injectable radiosensitizer suitable for clinical use. To achieve effective radiosensitization, it is critical to achieve a sufficient intratumoral GNP uptake and uniform distribution prior to radiation therapy. Therefore, in-vivo imaging of GNP distribution is the focus of many research groups. In this research we developed two hybrid bi-metallic nanoparticles — Zn@Au (Zn core and Au shell) and Cu@Au. When irradiated with protons or alpha particles, the Zn and Cu cores are activated to decay with positron emission with relatively long half-lives. Therefore, PET imaging shows the in-vivo distribution of those injected nanoparticles. These hybrid nanoparticles provide nearly identical radiosensitization as GNPs. After patient injection, their in-vivo distribution can be monitored until the optimal intra-tumoral uptake is achieved and then radiation therapy can be applied for optimal treatment boost.

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:

Joint Physics/Chemistry Department Seminar:

Abstract:

Recent technological advances in key components used in spectroscopic analysis have allowed the application of spectroscopy to samples smaller in size and concentrations than previously possible. Tissue and art samples have been analyzed utilizing these new tools to demonstrate the ability to chemically characterize samples beyond the diffraction limit. For Raman analysis, surface enhanced Raman spectroscopy (SERS) has become an important tool for facilitating the transition of spectroscopy to the biomedical and heritage communities. Current western blot and ELISA method analysis techniques have been shown to be inferior with respect to multiplexed analysis and sensitivity when compared to the newly implemented resonance SERS methods.

Note: Refreshments will be served at 3:00 pm in PS 105.

Oklahoma State Physics Department

Seminars and Colloquia, March 2-6, 2015

APS March Meeting

Oklahoma State Physics Department

Seminars and Colloquia, March 9-13, 2015

Physics Colloquium:

Canceled, as speaker was unable to come.

Oklahoma State Physics Department

Seminars and Colloquia, March 16-20, 2015

Spring Break

Oklahoma State Physics Department

Seminars and Colloquia, March 23-27, 2015

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

Experimental nuclear physics is a rich field with many applications to basic science, technology and national security.  Low-energy nuclear physics is experiencing tremendous growth with coming advances in the field of radioactive ion beams.  Experimentalists are probing nuclear structure far from stability to better understand nuclear processes in the stars.  Additionally, cutting edge detectors from particle physics are being employed to increase our understanding of fundamental nuclear reactions critical to national security.  A selection of experiments highlighting these advances will be presented.  Special attention will be given to the detectors as well as benefits to the broader community.

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.

OU/OSU Condensed Matter Physics Seminar:

Oklahoma State Physics Department

Seminars and Colloquia, March 30-April 3, 2015

Physics Colloquium:

Abstract:

The whispering gallery modes of micro-disk cavities can have very high quality (Q) factors and small mode volumes, which can interact with single optical emitters and form ideal cavity electrodynamical systems. Such high-Q micro-disk cavities have also been widely used for ultra-sensitive biosensors, low-threshold and narrow linewidth lasers, frequency comb, and cavity optomechanics applications.

In this talk, I will present how such high-Q micro-disk cavities are made and some of their 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, April 6-10, 2015

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Abstract:

The NOvA experiment is studying neutrino oscillations using the NuMI neutrino beam produced at Fermilab.  It consists of two functionally identical liquid-scintillator tracking calorimeters, and is optimized for finding electron neutrino appearance in a beam dominated by muon neutrinos.  A near detector, located at Fermilab, is used to characterize the beam before oscillations.  The oscillation parameters are extracted by observing the beam with the far detector 810 km away in northern Minnesota.  In this talk, I will present an overview of the NOvA experiment, review the techniques used to identify and reconstruct neutrino interactions, and describe the expected sensitivity of NOvA.

Physics Colloquium:

Abstract:

The 1998 discovery that neutrinos of different flavors oscillate into each other is among the most exciting developments in the recent history of particle physics.  It resolved long-standing anomalies in the flux of neutrinos originating from the sun and produced by the interaction of comic rays in the upper atmosphere.  Neutrino oscillations may also hold the key to a long-standing mystery:  why is there more matter in the universe than anti-matter?  NOvA is the latest in a series of experiments designed to study this phenomenon.  In this talk, I will introduce the concept of neutrino oscillations, present an overview of the NOvA experiment and its expected sensitivity, and touch briefly on future prospects for progress in this field.

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 13-17, 2015

Physics Colloquium:

Abstract:

A spinor Bose–Einstein condensate (BEC) confined by optical lattices has become one of the fastest-moving research frontiers in the past fifteen years. Our experimental data have demonstrated a novel quantum phase transition in steady states of lattice-confined spinor BECs, and confirmed an interesting lattice-tuned separatrix in phase space. The steady states are found to depend sigmoidally on the lattice depth and exponentially on the magnetic field, which is very different from a well-known mean-field prediction. We have also introduced a phenomenological model that describes our data without adjustable parameters.

Abstract:

After over 60 years since the first discovery of Nuclear Magnetic Resonance (NMR), it is still a powerful technique for biophysical and biochemical studies. Elucidating protein structure is the key to understand function. We applied both solid-state and solution NMR to two different protein systems. The first case we show is Perilipin 1 (PLIN1), a membrane protein bound to the single layer lipid membrane in the organelle lipid storage droplet in adipocytes. We combined experimental solid-state NMR data with molecular dynamics (MD) simulations to investigate the membrane-anchoring motif of this protein and how it is related to its function. In the second case, SHetA2 is a small flexible heteroarotinoid that has shown promising cancer prevention and therapeutic activities. It was shown to be able to bind to heat shock protein 70 family member Mortalin. By applying solution NMR chemical shift perturbation, we demonstrated the binding sites of SHetA2 on Mortalin and how this interaction leads to the disruption of the interaction between Mortalin and its substrate p53 thus leading to cell apoptosis.

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 20-24, 2015

Physics Colloquium:

Abstract:

I would never had imagined doing geometry for a living while taking my first course in geometry in high school, and carbon-based materials (fullerenes, carbon nanotubes, graphene) provided my first glimpse of how shape can very well determine materials properties about a decade ago.

In 2002, Saito proposed that one could understand changes in the electronic properties of carbon nanotubes as they couple to structural vibrations (phonons), as if these vibrations were creating electromagnetic fields that electrons on the nanotube felt and responded to.

This idea took a strong resurgence in 2009–2010, when Vozmediano, Katsnelson, Geim and Guinea proposed to create very large (pseudo-)magnetic fields by deforming graphene: The enticing part of their proposal was that fields equivalent to hundreds of Tesla should in principle be achievable on this material; an interesting possibility because most labs have few-Tesla magnets (the largest magnetic fields in a dedicated Lab in Florida reach about 30 Tesla, tops).

By the end of 2011 I had a close look at these theories: The intriguing aspect was that Saito’s and the following theories were all built on a continuum, as if atoms were not there. Something that started as a curiosity and a game with a mechanical engineer friend of mine turned into a few publications, an international Workshop, and the motivation to keep going: The basic idea is that atoms create a valid (discrete) geometry: This discrete geometry then serves as a new foundation to reformulate some of these theories and to correlate materials properties to changes in these materials’ shape.

1. Discrete differential geometry. Bobenko, Schröder, Sullivan, Ziegler, Eds. Birkhäuser (Basel).
2. “Strain-engineering of graphene’s electronic structure beyond continuum elasticity.” Barraza-Lopez, Pacheco-Sanjuan, Wang, and Vanevic. Solid State Comm. 166, 70 (2013).
3. “Quantitative chemistry and the discrete geometry of conformal atom-thin crystals.” Pacheco Sanjuan, Mehboudi, Harriss, Terrones, and Barraza-Lopez. ACS Nano 8, 1136 (2014).
4. “Strain and the optoelectronic properties of nonplanar phosphorene monolayers.” Mehboudi, Utt, Terrones, Harriss, Pacheco SanJuan, and Barraza-Lopez. PNAS (in press, 2015).

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 27-May 1, 2015

Prefinals Week

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Abstract:

Supersymmetry is one of the most interesting theories beyond the Standard Model, solving the hierarchy problem and providing an explanation for Dark Matter (DM). Both the ATLAS and the CMS collaborations pursued a rich search programme to discover Supersymmetry during Run 1 of the Large Hadron Collider (LHC). In absence of any significant deviation of the data from the Standard Model (SM) prediction, stringent limits were placed in some specific supersymmetric models. This talk will present a summary of constraints (from DM relic density, Higgs discovery, low-energy observables and LHC Run 1 data) on a particular variant of supersymmetric model namely, constrained Minimal Supersymmetric Standard Model (cMSSM). We will also discuss a novel signature for detection of cMSSM at the LHC Run 2.

Oklahoma State Physics Department

Seminars and Colloquia, May 4-8, 2015

Finals Week

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, May 11-15, 2015

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, May 18-22, 2015

1^st OSU Biophysics Symposium on Protein Structure, Dynamics & Function:

348B Noble Research Center, May 21^st, 2015

Hosted by the Departments of Physics, Chemistry, Biochemistry, and Microbiology, Oklahoma State University

Keynote speaker: Professor Wei Wang, Nanjing University, China

Contact person: Dr. Smita Mohanty, Department of Chemistry. Email: Smita.Mohanty@okstate.edu.

Oklahoma State Physics Department

Seminars and Colloquia, May 25-29, 2015

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 1-5, 2015

OU/OSU Condensed Matter Physics Seminar:

Abstract:

It has been recently realized that materials with strong spin orbit coupling can lead to novel states of matter such as topological insulators and superconductors. This exciting development might lead to a number of useful applications ranging from spintronics to quantum computing. Here, we present epitaxial growth of near surface InAs heterostructures where the structure is designed such that the charge distribution is mainly confined in InAs but has a non-zero value at the surface. This band engineering allows us to make ohmic contact to the 2DES while keeping the electron mobilities well above traditional surface structures. In addition, the Rashba parameter measured from weak antilocalization analysis exhibit a very large spin-orbit coupling due to highly asymmetric potentials near surface. We also show that near perfect interface and a highly transparent contact can be achieved using epitaxial growth of aluminum on near-surface InAs 2DESs. Indeed, superconductor-semiconductor-superconductor junctions fabricated on these wafers exhibit a supercurrent with superior properties compared to ex-situ deposition of superconducting metals. The supercurrent flowing through the semiconductor can be controlled by a gate voltage making a transistor where the current can be turned “off” and “on”. Our results show that these new systems could provide new possibilities to study new quantum transport phenomena in addition to topological superconductivity.

Oklahoma State Physics Department

Seminars and Colloquia, June 8-12, 2015

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 15-19, 2015

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 22-26, 2015

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 29-July 3, 2015

No talks scheduled.

Last Updated:

jhhp@jperk.phy.okstate.edu