Seminars and Colloquia, July through December, 2016


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Seminars and Colloquia, Typical Week:


Oklahoma High Energy Physics Seminar on Talk-Back Television:

Date:Thursday
Time:1:30-3:00 PM
Place:106 B Studio Room, Classroom Building, OSU
& Nielsen Hall, Room 103, OU
Inquiries: kaladi.babu@okstate.edu or kao@nhn.ou.edu

Physics Colloquium:

Date:Thursday
Time:3:30-4:30 PM
Place:PS 110
Inquiries: TBA@okstate.edu or perk@okstate.edu

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

Date:Friday (bi)weekly
Time:2:30 PM
Place:PS 147
Inquiries: perk@okstate.edu

Oklahoma State Physics Department

Seminars and Colloquia, July 4-8, 2016


Physics PhD Thesis Defense:

Speaker:Saki Khan
Department of Physics
Oklahoma State University
Date:Thursday, July 7, 2016
Time:2:00 PM
Place:PS 147
Title:Unification and Physics Beyond Standard Model

Physics PhD Thesis Defense:

Speaker:Jiating Ni
Department of Physics
Oklahoma State University
Date:Thursday, July 8, 2016
Time:9:00 AM
Place:PS 147
Title:Initial State Dependance of a Quantum Ratchet

Oklahoma State Physics Department

Seminars and Colloquia, July 11-15, 2016


Physics PhD Thesis Defense:

Speaker:Khoa Bui
Department of Physics
Oklahoma State University
Date:Thursday, July 12, 2016
Time:2:00 PM
Place:PS 147
Title:Induced Transparency and Pulse Delay Plus Induced Absorption and Pulse Advancement Using the Orthogonally Polarized Whispering Gallery Modes of a Single Microresonator

Oklahoma State Physics Department

Seminars and Colloquia, July 18-22, 2016


No talks scheduled.


Oklahoma State Physics Department

Seminars and Colloquia, July 25-29, 2016


No talks scheduled.


Oklahoma State Physics Department

Seminars and Colloquia, August 1-5, 2016


No talks scheduled.


Oklahoma State Physics Department

Seminars and Colloquia, August 8-12, 2016


No talks scheduled.


Oklahoma State Physics Department

Seminars and Colloquia, August 15-19, 2016


First Week of Classes


Joint Physics Colloquium and Chemistry Seminar:

Speaker:Dr. Pavel V. Avramov
Department of Chemistry and Green-Nano Materials Research Center
Kyungpook National University, Daegu, South Korea
Date:Thursday, August 18, 2016
Time:3:30 PM
Place:PS 110
Title:Quantum Stability of Low-Dimensional Nanostructures: The Limitations of Periodic Boundary Conditions

Abstract:

Quantum stability of atomic and electronic structure of low-dimensional structures is the key point since the discovery of a variety of 1D and 2D nanowires, nanotubes, one-atom thick films (e.g. graphene and h-BN) and complex low-dimensional heterostructures. The great progress to describe and interpret the structure and properties of low-dimensional nanostructures has been achieved by electronic structure calculations of perfect 1D and 2D infinite crystalline lattices, for which an implementation of periodic boundary condition approximation can cause artificial structural and magnetic order stabilization. There are several basic mechanisms of structural and magnetic order instability of low-dimensional structures. In particular, quantum destabilization of atomic structure of low-dimensional nanoclusters with multiple non-equivalent sublattices can be caused by translation symmetry breakdown. The asymmetry of zig-zag h-BN, h-SiC or fluorinated nanoribbon edges causes a uniform structural curvature with considerable out-of-the-plane bending, which results in breakdown of translational periodicity. Another mechanism of translational symmetry breakdown in low-dimensional carbon pentagon-constituted nanostructures with multiple sp2/sp3 sublattices. It was found that finite nanoclusters suffer strong uniform unit cell bending followed by breaking of the crystalline lattice linear translation invariance. At one-electron level of theory, a perfectly flat lattice is just a regular point on a potential energy surface with non-zero derivative, rather than an extreme point like global or local minimum or transition state. The lattice bending along two perpendicular directions leads to formation of nanotubes with potential energy crossing at zero curvature. Application of von Neumann–Wigner theorem to large-diameter tubes proves that 2D sp2/sp3 nanostructures are correlated transition states between two symmetrically equivalent bent structures.

Note: Refreshments will be served in Physical Sciences Room 147 at 3:00 PM.


Oklahoma State Physics Department

Seminars and Colloquia, August 22-26, 2016


Second Week of Classes


Oklahoma State Physics Department

Seminars and Colloquia, August 29-September 2, 2016


Condensed Matter Physics Seminar:

Speaker:Dr. Mario F. Borunda
Department of Physics
Oklahoma State University
Date:Friday, September 2, 2016
Time:1:00 PM
Place:PS 148, OSU
& Nielsen Hall, Room 103, OU
Title:Raman Spectroscopy in Graphene

Abstract:

Raman spectroscopy plays a key role in studies of graphene and related carbon systems. Graphene is perhaps the most promising material of recent times for many novel applications, including electronics. In this talk, I will present how the traditional and well established Kramers–Heisenberg–Dirac (KHD) Raman scattering theory (1925–1927) was extended to crystalline graphene.


Oklahoma State Physics Department

Seminars and Colloquia, September 5-9, 2016


Labor Day Break: Monday, September 5


Physics Colloquium:

Speaker:Dr. Gregory J. Quarles
Chief Scientific Officer
The Optical Society (OSA), Washington, DC
Date:Thursday, September 8, 2016
Time:3:30 PM
Place:PS 110
Title:Transparent Polycrystalline Materials:
From Nanopowder Science to Next Generation Devices

Dr. Quarles is the 2016 Physics Distinguished Alumni & Hall of Fame Inductee.

Introduction: A Random Walk: From OSU to OSA

My path from student in Stillwater to Chief Scientific Officer at The Optical Society in Washington, DC will be reviewed briefly before presenting my colloquium.

Abstract:

The thrust of this overview will focus on transparent polycrystalline optical materials, ranging from laser hosts to scintillators to window and dome materials. Comparisons of the spectroscopic, mechanical, thermo-optic and laser performance properties between single crystal and ceramic oxide gain materials will be presented. The first demonstration of laser-grade optical ceramics took place in 1995 by Ikesue with Nd-doped YAG. Over the past decade, a number of studies have shown that there are several techniques for processing the nanopowders that are the precursors to the fabrication of the polycrystalline laser hosts. Unique characteristics include achieving higher doping levels of the laser active impurities than can typically be obtained through standard Czochralski crystal growth techniques. Other unique manufacturing opportunities include uniform distributions of the active ions across the entire cross section of the polycrystalline pieces. Transparent ceramics can be produced by starting with phase-pure-oxide powders, or by several different reactive approaches in which a mixture of metal oxides are sintered. Utilization of these various nanopowder preparation technologies has led to advanced development and demonstration of large-scale materials utilized in scintillator applications, or as transparent optics on various military platforms. The rapid global growth and characterization of these materials over the past twenty years will be highlighted. The applications of these polycrystalline materials will be reviewed to provide a context for next-generation evolutions of various laser, imaging and transmissive optical systems.

Note: The traditional student-speaker chat will begin in Physical Sciences Room 147 at 3:00 PM. All students are welcome! Refreshments will be served.


Oklahoma State Physics Department

Seminars and Colloquia, September 12-16, 2016


No talks scheduled.


Oklahoma State Physics Department

Seminars and Colloquia, September 19-23, 2016


Physics Colloquium:

Speaker:Dr. Carlos E. González-Lepera
Director, Cyclotron Radiochemistry Facility
Department of Nuclear Medicine
The University of Texas MD Anderson Cancer Center
Date:Thursday, September 22, 2016
Time:3:30 PM
Place:PS 110
Title:Production of Positron Emitting Radioisotopes

Abstract:

My talk will discuss basic principles and technical aspects for the production of positron emitting radioisotopes for human use using a medical cyclotron.

Short Bio:

Carlos received a Master’s Degree in 1979 and a Doctoral Degree in Physics in 1983 from Instituto Balseiro and Centro Atómico Bariloche in Argentina. He spent four years as a postdoctoral and research assistant professor with the University of Tennessee, Knoxville working at Oak Ridge National Laboratory. After three years in private industry, he joined the University of Pennsylvania in 1991 as an Assistant Professor and Cyclotron Facility Manager where he developed and collaborated to develop new manufacturing techniques for PET radiopharmaceuticals. In 1998, he moved to The University of Texas Houston as an Associate Professor and Director of the Cyclotron Facility. He applied and obtained the first Nuclear Pharmacy License for distribution of [18F]FDG in the state of Texas. In 2002, he founded Cyclotope, a private nuclear pharmacy specializing in manufacturing of PET radiopharmaceuticals for routine clinical use and research purposes. He was president of Cyclotope until 2010 when he was appointed as Professor in Experimental Diagnostic Imaging and Nuclear Medicine at MD Anderson Cancer Center where he currently serves as Director of the Cyclotron Radiochemistry Facility.

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 26-30, 2016


Physics Colloquium:

Speaker:Dr. Congjun Wu
Department of Physics
University of California at San Diego
Date:Thursday, September 29, 2016
Time:3:30 PM
Place:PS 110
Title:Novel Orbital Phases of Cold Atoms in Optical Lattices — Unconventional BEC and Itinerant Ferromagnetism

Abstract:

Orbital is a degree of freedom independent of charge and spin, which plays important roles in magnetism and superconductivity in transition-metal-oxides. Recently, cold atom optical lattices have provided a new opportunity to investigate orbital physics. In this talk, we will present novel features of orbital physics that are not easily accessible in solid state systems.

We predicted that bosons, when pumped into high orbital bands of optical lattices, exhibit a class of novel superfluid states with complex-valued condensate wavefunctions spontaneously breaking time-reversal symmetry. These states are beyond the scope of the “no-node” theorem which applies to most well-known states of bosons. They exhibit unconventional symmetries in analogy to those of unconventional superconductivity. Our prediction has been experimentally observed by Hemerich’s group at Hamburg, who verified the p-wave symmetry through matter-wave interference and time-of-flight measurements. For orbital fermions, we focus on itinerant ferromagnetism (FM), i.e. FM with Fermi surfaces, which is a hard-core problem of strong correlation physics. The mean-field type Stoner criterion neglects correlation effects and thus too much overestimates the FM tendency. In fact, even under very strong repulsions, typically electrons in solids usually remain paramagnetic. Furthermore, the Curie–Weiss metal phase above Curie temperature is also a long-standing problem exhibiting a dichotomic nature: The spin channel is local moment-like and incoherent while the charge channel remains coherent. In spite of these difficulties, based on unambiguous non-perturbative studies, we predict the existence of the itinerant FM phase with high Curie temperatures in the p-orbital bands. We established a series of theorems proving the ground state FM phase over a large region of fermion fillings and performed sign-problem free quantum Monte-Carlo simulations. The critical and finite-size scalings of magnetic phase transitions are performed based on which Curie temperatures are extracted at high numeric precisions. Our results also apply to certain types of d-orbital transition-metal oxides in solid state systems.

  1. Congjun Wu, Unconventional Bose–Einstein Condensations Beyond the “No-node” Theorem, Mod. Phys. Lett. 23, 1 (2009), a brief review.
  2. Yi Li, E. H. Lieb, Congjun Wu, Exact Results on Itinerant Ferromagnetism in Multi-orbital Systems on Square and Cubic Lattices, Phys. Rev. Lett. 112, 217201 (2014).
  3. Shenglong Xu, Yi Li, Congjun Wu, Thermodynamic properties of a 2D itinerant ferromagnet — a sign-problem free quantum Monte Carlo study, Phys. Rev. X 5, 021032 (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, October 3-7, 2016


Physics Colloquium:

Speaker:Dr. Timothy A. Bolton
Department of Physics
Kansas State University
Date:Thursday, October 6, 2016
Time:3:30 PM
Place:PS 110
Title:TBA

Abstract:

TBA

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 10-14, 2016


Physics Colloquium:

Speaker:Dr. Tony Gherghetta
School of Physics and Astronomy
University of Minnesota
Date:Thursday, October 13, 2016
Time:3:30 PM
Place:PS 110
Title:TBA

Abstract:

TBA

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.


Fall Break: Friday, October 14


Oklahoma State Physics Department

Seminars and Colloquia, October 17-21, 2016


Physics Colloquium:

Speaker:Dr. Henry Segerman
Department of Mathematics
Oklahoma State University
Date:Thursday, October 20, 2016
Time:3:30 PM
Place:PS 110
Title:Design of 3D Printed Mathematical Art

Abstract:

When visualising topological objects via 3D printing, we need a three-dimensional geometric representation of the object. There are approximately three broad strategies for doing this: “Manual” — using whatever design software is available to build the object by hand; “Parametric/Implicit” — generating the desired geometry using a parametrisation or implicit description of the object; and “Iterative” — numerically solving an optimisation problem.

The manual strategy is unlikely to produce good results unless the subject is very simple. In general, if there is a reasonably canonical geometric structure on the topological object, then we hope to be able to produce a parametrisation of it. However, in many cases this seems to be impossible and some form of iterative method is the best we can do. Within the parametric setting, there are still better and worse ways to proceed. For example, a geometric representation should demonstrate as many of the symmetries of the object as possible. There are similar issues in making three-dimensional representations of higher dimensional objects. I will discuss these matters with many examples, including visualisation of four-dimensional polytopes (using orthogonal versus stereographic projection) and Seifert surfaces (comparing my work with Saul Schleimer with Jack van Wijk’s iterative techniques).

I will also describe some computational problems that have come up in my 3D printed work, including the design of 3D printed mobiles (joint work with Marco Mahler), “Triple gear” and a visualisation of the Klein Quartic (joint work with Saul Schleimer), and hinged surfaces with negative curvature (joint work with Geoffrey Irving).

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 24-28, 2016



Oklahoma State Physics Department

Seminars and Colloquia, October 31-November 4, 2016



Oklahoma State Physics Department

Seminars and Colloquia, November 7-11, 2016


Oklahoma High Energy Physics Seminar on Talk-Back Television:

Speaker:Dr. David Jamin
Department of Physics
Oklahoma State University
Date:Thursday, November 10, 2016
Time:1:30 PM
Place:PS 148, OSU
& Nielsen Hall, Room 103, OU
Title:Overview of Higgs Boson Search in ATLAS in Associated Production Decay Channel VH and H→bb

Abstract:

This presentation will review the latest results of Higgs boson search in ATLAS in one of the most important and still undiscovered channel : VH with H→bb. An overview of the 3 channels analysis (leptonic decays only of the vector boson V) will be shown as well as the Standard Model constraint checks that have been performed.


Oklahoma State Physics Department

Seminars and Colloquia, November 14-18, 2016



Oklahoma State Physics Department

Seminars and Colloquia, November 21-25, 2016


Thanksgiving Break: November 23-25


Oklahoma State Physics Department

Seminars and Colloquia, November 28-December 2, 2016



Oklahoma State Physics Department

Seminars and Colloquia, December 5-9, 2016


Prefinals Week

No talks scheduled


Oklahoma State Physics Department

Seminars and Colloquia, December 12-16, 2016


Finals Week

No talks scheduled


Oklahoma State Physics Department

Seminars and Colloquia, December 19-23, 2016


No talks scheduled


Oklahoma State Physics Department

Seminars and Colloquia, December 26-30, 2016


No talks scheduled


Last Updated:

jhhp@jperk.phy.okstate.edu