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

Oklahoma State Physics Department

Seminars and Colloquia, January 26-30, 2009

Physics Colloquium:

Abstract

Physics Colloquium:

Abstract

Oklahoma State Physics Department

Seminars and Colloquia, February 2-6, 2009

Physics Colloquium:

Abstract

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

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

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

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

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

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

Oklahoma State Physics Department

Seminars and Colloquia, April 6-10, 2009

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

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

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

No talks scheduled.

Oklahoma State Physics Department

Seminars and Colloquia, May 11-15, 2009

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

No talks scheduled.

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