Seminars and Colloquia, January through June, 2009

• This Week's schedule.
• Earlier Semesters.
• Typical Week's schedule.
• January 1-2, 2009's schedule.
• January 5-9, 2009's schedule.
• January 12-16, 2009's schedule.
• January 19-23, 2009's schedule.
• January 26-30, 2009's schedule.
• February 2-6, 2009's schedule.
• February 9-13, 2009's schedule.
• February 16-20, 2009's schedule.
• February 23-27, 2009's schedule.
• March 2-6, 2009's schedule.
• March 9-13, 2009's schedule.
• March 16-20, 2009's schedule.
• March 23-27, 2009's schedule.
• March 30-April 3, 2009's schedule.
• April 6-10, 2009's schedule.
• April 13-17, 2009's schedule.
• April 20-24, 2009's schedule.
• April 27-May1, 2009's schedule.
• May 4-8, 2009's schedule.
• May 11-15, 2009's schedule.
• May 18-22, 2009's schedule.
• May 25-29, 2009's schedule.
• June 1-June 5, 2009's schedule.
• June 8-12, 2009's schedule.
• June 15-19, 2009's schedule.
• June 22-26, 2009's schedule.
• June 29-July 3, 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 Nanonet Informal Seminar:

Oklahoma State Physics Department

Seminars and Colloquia, January 1-2, 2009

No talks scheduled

Oklahoma State Physics Department

Seminars and Colloquia, January 5-9, 2009

No talks scheduled: Prelim Exams

Oklahoma State Physics Department

Seminars and Colloquia, January 12-16, 2009

First Week of Classes

Oklahoma State Physics Department

Seminars and Colloquia, January 19-23, 2009

Physics Colloquium:

Abstract:

The environment and biochemical cellular processes determine the cells’ fate in the body, shaping them into a system of interconnected biocomputers. These biocomputers integrate the cues from their microenvironment and respond through cascades of gene regulatory networks. Understanding cell signaling and the responses to the environment could facilitate drug discovery for the treatment of disease.

My talk will focus on our revolutionary technology that tackles both ends of the regulatory response problem. On the one hand, we use arrays of holographic optical traps to organize cells with nanometer precision into (permanent) synthetic tissue in a hydrogel matrix to study cell-to-cell communication. For example, as a model for paracrine signaling between neighboring cells, we have analyzed “quorum sensing” in genetically engineered bacteria. Quorum sensing is a regulatory mechanism that launches a coordinated multi-cellular response that depends on the population density—making the sum greater than the cellular parts. On the other hand, we use nanopores in synthetic membranes to study interactions that govern the gene regulation at a single molecule level. I will describe our efforts in using the synthetic nanopores to study the effects of biochemical modifications such as methylation on DNA molecules. I will also present our results on analyzing DNA-protein interaction using synthetic nanopores.

Oklahoma State Physics Department

Seminars and Colloquia, January 26-30, 2009

Physics Colloquium:

Abstract:

I will present experimental studies that we have carried out on the generation and delay of highly entangled beams of light, know as twin beams. The quantum correlations present in twin beams have recently generated great interest due to their applications in quantum information, quantum imaging, and quantum computing. In the first part of the talk I will show that non-degenerate four-wave mixing (4WM) in a rubidium vapor cell is an excellent source of continuous-variable (CV) entangled twin beams, with an intensity-difference noise of less than 13% of the classical shot-noise level. Unlike other systems that rely on the use of a cavity, the system that we use can support a large number of spatial modes. This leads to spatial quantum correlations and makes it possible to produce CV entangled images. In the second part I will show that, in addition to generating entangled twin beams, the 4WM process in a vapor cell can act as a tunable delay line for CV entanglement without significant degradation. This has allowed us to delay entangled images. Finally, I will give a quick overview of some possible future applications for these highly entangled multi-spatial-mode twin beams.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

Quantum optomechanics—the optical manipulation of mechanical systems in the quantum regime—is a rapidly emerging field at the intersection of atomic physics, nanoscience, quantum optics, and gravitational wave interferometry. After a general introduction to the subject I will describe some specific results with implications for the coherent control of atoms and molecules, precision sensing, and quantum information science.

Oklahoma State Physics Department

Seminars and Colloquia, February 2-6, 2009

Physics Colloquium:

Abstract:

Spinor condensates of F=1 sodium atoms display rich spin dynamics due to the antiferromagnetic nature of the interactions in this system. We make a continuous and minimally destructive measurement of the spin dynamics on a single evolving spinor condensate. This technique provides a sharp signature of a magnetically tuned boundary in phase space between the oscillating and running phase solutions. We also measure the time evolution of atom number fluctuations, which uncovers a novel dissipation-driven boundary in phase space. We introduce a phenomenological model to describe the observed energy dissipation. This allows us to precisely reveal phase space dynamics during spin mixing in the condensate.

Oklahoma State Physics Department

Seminars and Colloquia, February 9-13, 2009

Physics Colloquium:

Abstract:

Fascination with nucleic acids has transcended their role as the carrier of genetic information. Nucleic acids are being discovered that orchestrate vital biological processes. They are being pursued as promising therapeutic agents, versatile bioengineering materials, and model biophysical systems. Despite intense interest and extensive effort, physical understanding of the molecular forces driving DNA assemblies remains elusive. Towards this goal, we have combined small angle x-ray scattering methods and theories of polyelectrolytes to quantify how the force between nucleic acids is modulated by different cations. Our measurements of inter-DNA repulsive and attractive forces put current physical theories to stringent test and bear biological and therapeutic implications. Future work aims to dissect the individual roles of DNA, ion, and solvent in wielding molecular forces, and to probe the structure and energetics of tightly packaged DNA in cells and viruses.

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:

In this talk I will describe recent progress in the preparation of ultracold dipolar gasses. First I will review various approaches to creating ultracold gasses in polar molecules, with an emphasis on our work on photoassociation of NaCs. I will then describe a novel trap for the molecules known as the “TWIST.” In the second part of the talk I will describe our work on the quantum spiN-state engineering of an atomic BEC.

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, 2009

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

Although graphene has been studied experimentally for only about five years, its band structure has been studied for over fifty years. A common approach to obtain the band structure of graphene is to apply nearest-neighbor, tight-binding theory. This theory also allows approximate band structures of graphene nanostrips (also known as graphene nanoribbons) to be calculated. Because of the existence of edge effects not captured in this theory, however, these band structures have turned out to be inadequate near the Fermi level.

In this seminar, more accurate models will be presented for both armchair-edge and zigzag-edge nanostrips that consider third-nearest-neighbor interactions, edge distortions, and spin-polarization. The band structures from these models are all in excellent agreement with those obtained using local spin-density-functional theory. Finally, potential applications based on these models 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, February 23-27, 2009

Quantum Physics Seminar

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium

Abstract:

While instruction is only one of the three dimensions of our employment, much of the public believes it is the only dimension. So questions concerning the quality of instruction have led to increased scrutiny (worldwide). Witness the recent Learning Outcome Assessment we are required to perform for our undergraduate and graduate programs. This assessment need not be burdensome, if we generate certain kinds of artifacts in some courses. Take heart, physicists have been leading the present wave of education reform (e.g. see Declining by Degrees).

In this talk my experiences for courses taught in the last two years, each one a new course and a new preparation, will be presented. One involves students teaching, another gives no grades except for the final examination, the third teaches the physics necessary to be good citizens, and finally an optics course with hands-on homework.

Attention has been given to generating the kind of artifacts that are useful for assessment. The learning goals for each course and how they are measured is presented. I am looking for methods that potentially are better than current teaching methods in terms of student learning but require equal or reduced time commitment.

Finally, we need not teach alone, especially since I hear good stuff being done by others. Please come, comment, critique and share your own successes and challenges. The public is watching us more than ever and sharing information is the only way we will keep (way) ahead.

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 2-6, 2009

Physics Colloquium

Abstract:

The basic physics involved in the quantum spin Hall effect appeared in the topological insulators will be briefly introduced. Our recent work on the effects of dephasing and disorder on the quantum spin Hall effect and their experimental consequences will be discussed in light of the recent experimental results [Science 318, 766 (2007)].

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 9-13, 2009

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

An entangled quantum system can sometimes share a state over macroscopic distances so that a measurement in one location can suddenly collapse the quantum state of another component of the system over long distances. We will discuss some insights obtained from recent research on why this behavior is detected only rarely in macroscopic 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.

Quantum Physics Seminar

Speaker:	Dr. Carlos R. Stroud
	The Quantum Optics Group
	Department of Physics and Astronomy
	University of Rochester
Date:	Friday, March 13, 2009
Time:	3030 PM
Place:	147 PS
Title:	Decoherence, Decoherence-Free Subspaces and Sudden Entanglement in Oscillators Coupled to Various Reservoirs

Abstract:

(Dr. Stroud) will discuss a series of calculations studying collections of oscillators coupled to Markovian and non-Markovian reservoirs at finite and zero temperatures and convex-roof extension calculations of the time dependent entanglement of these systems.

Oklahoma State Physics Department

Seminars and Colloquia, March 16-20, 2009

Spring Break

Oklahoma State Physics Department

Seminars and Colloquia, March 23-27, 2009

Society of Physics Students Meeting:

Dr. Summy will present an informal lecture and discussion with students about Bose-Einstein Condensates.

Note: Cookies and coffee will be served at 4:30 PM.

Physics Colloquium:

Abstract:

The first clue as to the existence of dark matter came from the measurements of the random velocities of the galaxies in the Coma cluster by Zwicky in 1935. However it was only in the early 1970’s that it was recognized that dark matter is comprised of weakly interacting particles, surviving as relicts of the big bang origin of the Universe. These particles triggered the formation of galaxies, formed halos enshrouding them, dominating their gravitational dynamics. To be able to detect these particles, and ascertain their identity through astronomical observations and laboratory experiments, it is important to understand the phase space structure of these dark matter halos.

The dynamical friction suffered by a massive astronomical body moving through a background distribution of particles, discovered by Chandrasekhar in 1942, provides a sensitive probe of the phase space structure of dark matter. In this colloquium we discuss the dynamical friction suffered by globular clusters orbiting inside the dwarf spheroidal galaxy in Fornax with a particular focus on the apparent paradox posed by the wide spatial distribution of the globular clusters within Fornax. Earlier estimates of the dynamical friction with simple models had indicated that the globular clusters would have migrated to the center of the dwarf galaxy well within the age of the Universe, posing a problem. We set the stage for these discussions with a brief review of the historical perspective and the current status of the studies of dark matter. Then we derive a model for the dark matter halo of Fornax based on a self-consistent theory that fits all the observations such as the profiles of luminosity and velocity dispersion of the stars. We then show that the application of Chandrasekhar’s formula yields very long time constants for inward migration, thereby resolving the paradox.

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 30-April 3, 2009

College of Engineering, Architecture & Technology Seminar:

Abstract:

Spherical and hemispherical-nose rod projectiles (steel or tungsten carbide) were dropped or fired into dry particulate media targets (glass beads or quartz Eglin sand; as-poured or vibratory packed) at velocities of 0-1,200 m/s. Particulate media deformation clearly reflects the expected dilatational or compaction responses, reinforcing the notional yield surface construct and showing a strong history/media preparation sensitivity. Prior reported exponential dependencies of penetration depth upon impact velocity are shown to be strongly depth (pressure) dependant. Such findings support and are validated by the research roadmap documented during the February 2009 Particulate Mechanics in Extreme Environments (PMEE 2009) Federal Agency research workshop. This roadmap will be presented to illustrate the potential research links that can enable robust engineering codes for particulate material design problems.

Refreshments at 2:30 p.m. in the ATRC Vogt Room.

Brief Biographical Sketch:

William L. (Bill) Cooper received the B.S. in Aerospace Engineering from the University of Notre Dame (1991); the M.S. in Mechanical Engineering from the University of Notre Dame (1992); and the Ph.D. in Mechanical Engineering from the University of California at Los Angeles (1996). He has served as a Quality Assurance and ESOH Division Chief and an Advanced Energetics Team Leader in the Air Force Research Laboratory at Eglin Air Force Base, Fl; in various senior and operations positions with NEXTEL; R&D Engineer and Program Manager in the Advanced Energetics Program as an Air Force Officer assigned to the Air Force Research Laboratory at Eglin AFB, FL; and as a Program Manager in the Improved Lethality Program as an Air Force Officer at the Wright Laboratory at Eglin Air Force Base, FL. In his current position, he is responsible for physics, chemistry, materials science and engineering of extremely high-rate, explosively-driven munitions materials. His current research involves high pressure/rate mechanics of particulate & granular materials; mechanics in extreme environments; and measurement of material properties of high-strength concrete, explosives, particulate media, advanced steels, composite and heterogeneous media.

Society of Physics Students Meeting:

Dr. Nandi will present a second informal lecture and discussion with students about Extra Dimensions.

Note: Cookies and coffee will be served at 4:30 PM.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Oklahoma State Physics Department

Seminars and Colloquia, April 6-10, 2009

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Colloquium:

Abstract:

The energy scales to be probed by experiments at the Large Hadron Collider (LHC) at the CERN Laboratory in Geneva, Switzerland will reproduce the conditions present at the time of the very early universe. These experiments will address some of the most fundamental questions in particle physics: can all the forces be unified into a single unified framework? What do the properties of particles tell us about the nature and origin of matter? What can they tell us about the nature of space-time itself? What is the nature of dark matter? I will discuss how the ATLAS experiment can address some of these questions together with an overview of the status of the experiment which is preparing for the anticipated start of data taking in the fall of 2009.

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, 2009

Physics Colloquium:

Abstract:

An abundance of evidence shows that Standard Model (SM) particles make up only one-fifth of the matter density of the universe, while the remainder is likely some unknown elementary particle.

Supersymmetric theories of particle physics fix a host of problems in the SM, while receiving some experimental support, and predicting at least three candidate particles for cold dark matter (CDM) in the universe. One CDM particle- the lightest neutralino-can be searched for directly via nuclear scattering of Big Bang relics in underground experiments, via indirect searches for gamma rays or antimatter which results from dark matter annihilations in the galactic halo, or via direct dark matter particle production at accelerators such as the CERN LHC, which will turn on next year.

Another possibility for dark matter comes from the axion/axino multiplet.

I summarize in this talk the theoretical background and experimental search possibilities with regards to supersymmetric dark matter.

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, 2009

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Abstract:

I shall discuss some aspects of astroparticle physics, mentioning the problems of baryogenesis, dark matter and dark energy, which cannot be solved by the standard model (SM). Since the non-zero neutrino masses are the only experimental indication for physics beyond the SM, there are attempts to solve all these three problems with extensions of the SM, which are motivated by the neutrino masses. We shall explain how the models of neutrino masses could be related to these problems of astroparticle physics, highlighting some of the models that provides testable signatures at LHC.

Physics Colloquium:

Abstract:

The quantum confinement provided by a semiconductor quantum dot suppresses much of the many body physics associated with the coherent nonlinear optical response observed in higher dimensional systems. This makes them attractive for potential device applications where atomic like properties, such as high Q resonances, strong optical interactions, or long quantum coherence times, could be important.  In this talk, we present recent results demonstrating high field effects beyond Rabi oscillations including the Mollow absorption spectrum showing gain without inversion, dark state formation in single electron doped dots, and suppression of nuclear fluctuations by the hyperfine interaction leading to longer electron spin coherence times.

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, 2009

Prefinals Week

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Abstract:

Due to the large top quark production cross section at the LHC, the ATLAS experiment is expected to have enough statistics to measure top quark properties even at initial luminosities. The main focus of my presentation will be on the measurements of top quark pair cross section. I will present the current situation with top quark cross section measurements at Dzero experiment and recent studies performed in ATLAS with emphasis on measurements with data that will be collected in the first year of the LHC run. The potential of using the top quark events for the b-tagging calibration will be also briefly discussed.

Quantum Optics Seminar:

Abstract:

Dr. Schilling will present a scheme which uses projective measurements to transfer N remote qubits into a common state. In this scheme, the choice of measurement parameters determines the final state of the qubits, thereby providing a way to produce a certain state without any interaction with or among the qubits. He will show a way of using this technique to generate a coupled basis of the N-qubit Hilbert space, namely all total angular momentum eigenstates.

A. Maser et. al., Phys. Rev. A 79, 033833 (2009)

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 4-8, 2009

Finals Week

College of Engineering, Architecture & Technology Seminar:

Abstract:

Intermetallic compounds of the rare earth metals (R) with group 14 elements (T) at the R₅T₄ stoichiometry provide numerous opportunities to clarify structure-property relationships, and in the future to exploit this knowledge. The uniqueness of these compounds lies in well-defined, self-assembled layers composed of R and T atoms coupled with the flexibility to modify their arrangements in closely related structures using a variety of triggers. In this presentation we will be concerned with some recently discovered, extraordinarily interesting magnetic and electronic transport phenomena that are related to targeted structural and microsctructural modifications that facilitate an unprecedented level of control over the physical behaviors of these compounds.

Refreshments at 2:30 p.m. in the ATRC Vogt Room.

Brief Biographical Sketch:

Dr. Pecharsky received his Ph.D. degree in Inorganic Chemistry in 1979 from the L’viv State University in the Ukraine (http://en.wikipedia.org/wiki/Lviv_University). He first joined the USDOE Ames Laboratory in 1993 as a Visiting Scientist, and then became an Associate Scientist in 1995. He has been a Senior Scientist at the DOE Ames Laboratory at Iowa State since 2000, and was appointed as the Anson Marston Distinguished Professor of Materials Science in the Department of Materials Science and Engineering in 2006. He does his research work at the USDOE Ames Laboratory, where he serves as one of 16 Field Work Proposal Leaders in two areas: magnetic materials and materials for hydrogen storage. His current research areas are magnetic refrigeration materials, energy conversion materials, and hydrogen storage materials. He and a colleague have discovered a new class of materials that display a “giant magnetocaloric effect.” This discovery has opened up an opportunity to rapidly develop the revolutionary magnetic refrigeration technology for consumer applications, including home refrigeration and freezing, home and automobile air conditioning, and commercial cooling, freezing and air conditioning. Magnetic refrigeration could reduce national demand for electricity by as much as 5%. Dr. Pecharsky is a member of several professional organizations, including the Materials Research Society; the Minerals, Metals and Materials Society; and the American Society for Engineering Education. He is the author or co-author of over 300 journal articles, 8 book chapters, and is the inventor or co-inventor of 13 issued patents.

Oklahoma State Physics Department

Seminars and Colloquia, May 11-15, 2009

College of Engineering, Architecture & Technology Seminar:

Abstract:

Self-healing materials, when damaged, are designed to sense the failure and respond in an autonomous fashion to restore structural function. Inspired by biological systems, synthetic self-healing materials represent a new paradigm in the design of polymer based composites. This presentation will summarize the different strategies and approaches to achieving self-healing functionality and discuss future directions in the nascent field. The focus will be on our results in a reinforced structural composite material in which a microencapsulated healing agent and a solid chemical catalyst are both dispersed in the polymer matrix phase. Healing is triggered by crack propagation through the microcapsules, which then release the healing agent into the crack plane. Subsequent exposure of the healing agent to the chemical catalyst initiates a ring-opening metathesis polymerization (ROMP) and bonds of the crack faces. The influence of healing agent chemistry and catalyst morphology on the ROMP kinetics and subsequent healing effectiveness will be discussed.

Refreshments at 2:30 p.m. in the ATRC Vogt Room.

Brief Biographical Sketch:

Professor Kessler is an expert in the mechanics, processing, and characterization of polymer matrix composites and nanocomposites. His research thrusts include the development of multifunctional materials (including the development of self-healing structural composites), polymer matrix composites for extreme environments, bio-renewable polymers and composites, and the evaluation of these materials using experimental mechanics and thermal analysis. These broad-based topics span the fields of organic chemistry, applied mechanics, and processing science. He has extensive experience in processing and characterizing thermosets including those created through ring-opening metathesis polymerization (ROMP), such as polydicyclopentadiene, and the cyclotrimerization of cyanate ester resins. In addition to his responsibilities as an assistant professor of Materials Science and Engineering at Iowa State University, he is an associate of the Department of Energy’s (DOE) Ames Laboratory and is an active affiliate of the Biocomposites Research Group of the Center for Crops Utilization Research at Iowa State. In his short academic career he has developed an active research group with external funding of over four million dollars—including funding from the National Science Foundation, ACS Petroleum Research Fund, Strategic Environmental Research and Development Program (SERDP), Department of Defense, and NASA. His honors include Young Investigator Awards from the Army Research Office and the Air Force Office of Scientific Research. In the past 3 years he has published nearly 30 journal papers. He holds three patents, has edited a book on the characterization of composite materials. He received MS and PhD degrees in Theoretical & Applied Mechanics from the University of Illionois, the BS degree from LeTourneau College.

College of Engineering, Architecture & Technology Seminar:

Abstract:

It is imperative that the future of integrated nano and micro systems relies on the fundamental understanding of manufacturing structures, related processes and measurements across the scale, signal and domain boundaries. This presentation will address ongoing projects related to the integration of micro and nana systems for multifunctional applications. The presentation will demonstrate roles of nano materials, micro and nano processing tools, nano manufacturing processes and system durability related to successful realization of integrated systems. Results also will be presented on the fundamental and applied science studies on nanocrystalline diamond (NCD) and microfabrication processes and characterization of mechanical, tribological, electronic transport, and bio-compatible properties. The unique properties of NCD make it a promising candidate for use as protective coating of machining tools, a hermetic, corrosion-resistant coating for biodevices, a cold-cathode electron source, and structural materials in micro-and nanoelectromechanical systems (MEMS/NEMS). The current science and technology of synthesis, characterization, and applications of NCD coatings for multifunctional applications will be discussed.

Refreshments at 2:30 p.m. in the ATRC Vogt Room.

Brief Biographical Sketch:

Dr. Ashok Kumar is a Professor in the Department of Mechanical Engineering, and at the University of South Florida, Tampa. Dr. Kumar is also an affiliated faculty member in the Nanomaterials and Nanomanufacturing Research Center (NNRC) and the Clean Energy Research Center (CERC). He received his B.S. and M.S. degrees from Indian Institute of Technology (Kanpur), and his Ph.D. from North Carolina State University, Raleigh. His research is focused towards development of surface engineered coatings for multifunctional applications. He has published 2 textbooks, edited 6 proceeding books, 3 invited review articles, 5 book chapters including 160 reviewed articles and has presented approximately 190 papers in regional and national conferences. He has received in excess of 7 million dollar of research funding as PI and more than 17 million dollars as Co-PI. His research has been supported from federal agencies (NSF, NASA, DOD and DOE) and private companies, such as, Sematech, Honeywell, General Motors, Lucent Technologies, Novellus, IBM, and Cabot Microelectronics etc. His honors include ASM Fellow, ASM-IIM Visiting Lecture Award Theodore and Venette Askounes Ashford Distinguished Scholar Award (2006), USF Outstanding Faculty Research Achievement Award USF President Faculty Excellence Award NSF Faculty Early CAREER Development Award National Research Council Twining Fellowship Award and, NSF and DOE EPSCoR Young Investigator Awards.

Oklahoma State Physics Department

Seminars and Colloquia, May 18-22, 2009

Physics Talk:

Oklahoma State Physics Department

Seminars and Colloquia, May 25-29, 2009

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 1-4, 2009

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 8-12, 2009

Abstract:

The dipole blockade, i.e. the inability to excite a second atom when the first atom has been excited has attracted a lot of attention lately [1-4]. In this talk, we report a number of unusual characteristics of the dipole blockade. We show how dipole blockade leads to quantum entanglement and antibunching of atoms. We further show how dipole blockade can be lifted by saturating the optical transitions.

References:

1. K. M. Birnbaum, A. Boca, R. Miller, A. D. Boozer, T. E. Northup and H. J. Kimble, “Photon Blockade in an Optical Cavity with One Trapped Atom”, Nature 436, 7047 (2005).
2. A. Gaetan, Y. Miroshnychenko, T. Wilk, A. Chotia, M. Viteau, D. Comparat, P. Pillet, A. Browaeys and P. Grangier, “Observation of collective excitation of two individual atoms in the Rydberg blockade regime”, Nat. Phys. 5, 115 (2009).
3. E. Urban, T. A. Johnson, T. Henage, L. Isenhower, D. D. Yavuz, T. G. Walker and M. Saffman, “Observation of Rydberg blockade between two atoms”, Nat. Phys. 5, 110 (2009).
4. T. Pohl and P. R. Berman, “Breaking the Dipole Blockade: Nearly Resonant Dipole Interactions in Few-Atom Systems”, Phys. Rev. Lett. 102, 013004 (2009).

Oklahoma State Physics Department

Seminars and Colloquia, June 15-19, 2009

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 22-26, 2009

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, June 29-July 3, 2009

College of Engineering, Architecture & Technology Seminar:

Abstract:

For many energy and electronic applications, single-crystal-like materials offer the best performance. However in almost all cases, the single crystal form of the relevant material is too expensive. Furthermore, the classic problem of the brittle nature of certain materials such as ceramic materials is often an issue. In addition, for many applications, very long or wide materials are required, a regime not accessible by conventional single crystal growth. This necessitates the use of flexible, large-area, long, single-crystal-like substrates for epitaxial growth of the relevant advanced material for the electronic or energy application in question. Since the factor determining suitability for applications is price/performance, the process used for fabrication of the artificial substrate needs to be very scalable and low-cost. We report here a method to form such biaxially-textured, polycrystalline substrates, referred to as Rolling-assisted-biaxially-textured-substrates (RABiTS). Details of substrate fabrication, the texture quality of the substrates, the nature of grain boundaries, and the range of materials that can be epitaxially grown on such substrates will be discussed. The RABiTS technique employs simple and industrially scalable thermomechanical processing routes to obtain long lengths of near single-crystal-like, cube-textured substrates. Epitaxial buffer layers of various cubic oxides (of rock salt, flourite, perovskite and pyrochlore crystal structures) are then deposited in a reel-to-reel configuration using web-coating employing electron-beam evaporation, sputtering or chemical solution deposition. As an example of a material for energy and electronic applications, results will be presented for growth of superconductors on such substrates. Finally, for many applications, incorporation of a 3D network of nanodots within a ceramic matrix is desired for optimization of physical properties or for enabling novel properties or phenomena. It will be shown that controlled incorporation of 3D self-assembled nanodots of one complex ceramic material (in this case of an insulating material) can be achieved within another complex ceramic material (within the superconductor layer) and this can very significantly enhance the superconducting properties. For both of these platform technologies (single-crystal-like substrates and 3D self-assembly of nanomaterials), wide ranging applications exist in electronic and energy sectors including applications in photovoltaics, ferroelectrics, multiferroics, and ultra-high density storage.

Refreshments at 2:30 p.m. in the ATRC Vogt Room.

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