Quantum information processing requires our ability to design, build and control devices at the quantum level. I will review our recent work in this direction using elementary building blocks: single electron, single spin, single exciton and single photon. Examples will cover lateral semiconductor and graphene quantum dots as quantum circuits based on electron spin and self-assembled quantum dots for single and entangled photon sources.
Events: Departmental Colloquia
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Semiconductor and graphene devices for quantum information processing
Guest: Dr. Pawel Hawrylak, National Research Council, Canada, Institute for Microstructural Sciences
Thursday, March 3, 2011 4:00 pm - 5:00 pm
Location: Physics 202 -
Computer Simulations of Critical Phenomena and Phase Behavior of Fluids
Guest: Dr. Kurt Binder, Institut für Physik, Johannes Gutenberg Universität Mainz and The Univeristy of Georgia, Department of Physics and Astronomy
Thursday, February 24, 2011 4:00 pm - 5:00 pm
Location: Physics 202Computer simulation techniques such as Monte Carlo (MC) and Molecular Dynamics (MD) methods yield numerically exact information (apart from statistical errors) on model systems of classical statistical mechanics. However, a systematic limitation is the restriction to a finite (and often rather small) particle number N (or box linear dimension L, respectively). This limitation is particularly restrictive near critical points (due to the divergence of the correlation length of the order parameter) and for the study of phase equilibria (possibly involving interfaces, droplets, etc.). Starting out with simple lattice gas (Ising) models, finite size scaling analysis have been developed to overcome this limitation. These techniques work for both simple Lennard-Jones fluids and their mixtures, including generalizations to
approximate models for quadrupolar fluids such as carbon dioxide, benzene etc. and various mixtures, whose phase behaviour can be predicted. A combination of MC and MD allows the study of dynamic critical phenomena, and specialised techniques (umbrella sampling plus
thermodynamic integration) yield the surface free energy of droplets as function of droplet size. Thus, computer simulation has become a versatile and widely applicable tool for the study of fluids. -
Non-equilibrium Statistical Mechanics: a growing frontier of “pure and applied” theoretical physics
Guest: Dr. Royce Zia, Virginia Polytechnic Institute and State University, Department of Physics
Thursday, February 17, 2011 4:00 pm - 5:00 pm
Location: Physics 202Founded over a century ago, statistical mechanics (SM) for systems in thermal equilibrium has been so successful that, nowadays, it forms part of our physics core curriculum. On the other hand, most of “real life” phenomena occur under non-equilibrium conditions. Unfortunately, statistical mechanics for such systems is far from being well established. The goal of understanding complex collective behavior from simple microscopic rules (of evolution, say) remains elusive. As an example of the difficulties we face, consider predicting the existence of a tree from an appropriate collection of H,C,O,N…atoms! Over the last two decades, an increasing number of condensed matter theorists are devoting their efforts to this frontier. After a brief summary of the crucial differences between text-book equilibrium SM and non-equilibrium SM, I will give a bird’s-eye view of some key issues, ranging from the “fundamental” to (a small set of ) the “applied.” The methods used also span a wide spectrum, from “easy” computer simulations to sophisticated field theoretic techniques. These will be illustrated in the context of an overview of our work, as well as a simple model for transport.
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Entrainment and horizontal cross flows and their affect on hydrothermal plume vertical velocity and temperature fluctuations
Guest: Dr. Daniela Di Iorio, University of Georgia, Department of Marine Sciences
Thursday, February 10, 2011 4:00 pm - 5:00 pm
Location: Physics 202Deep sea hydrothermal plumes are driven by gravitational buoyancy forces and may rise up to hundreds of meters above their orifice. Ambient ocean water is entrained into the plume during its ascent, which makes the plume diluted and cooled. Long term measurements of physical properties of hydrothermal plumes are limited and are important for understanding heat flow from the Earth’s interior. In Sept 2007 an acoustic scintillation system was used to specifically quantify the temporal variability of the vertical velocity and temperature fluctuations of the hydrothermal plume of Dante at 2155m depth. Six weeks of data was collected and using the space-time coherence of the acoustic amplitude signal, hourly vertical velocity measurements were obtained. Theoretical developments comparing acoustic forward scattering from turbulence and from particles show that suspended particles within the plume produce negligible amplitude fluctuations compared to turbulence modeled by an isotropic and homogeneous Kolmogorov model for the temperature variability.
The vertical velocity and temperature fluctuations show a significant negative correlation with the horizontal flow. The hydrothermal plume of Dante and its interaction with the horizontal flow within the Main Endeavour Field can be generalized as follows: 1) when the horizontal flow is weak (during the ebbing tide), less ambient ocean water is entrained into the plume. In such a case, the plume is faster and hotter and the temperature fluctuations increase within the plume; 2) when the horizontal flow is strong (during the flooding tide), more ambient ocean water is entrained into the plume. In such a case, the plume is slower
and cooler with reduced temperature fluctuations. Results from an integral plume model based on the conservation equations of mass, momentum, density deficit and dissolved tracers and taking into account ambient stratification and horizontal cross flows are compared with observations showing consistent results. -
Synthesizing arbitrary photon states
Guest: Dr. Max Hofheinz, CEA (Commissariat a l'energie atomique et aux energies alternatives)-Saclay, France
Thursday, February 3, 2011 4:00 pm - 5:00 pm
Location: Physics 202The favorite model systems of quantum mechanics, the two-level system and the harmonic oscillator, can be implemented in various experimental systems, but only become useful when their quantum states can be sufficiently well controlled. This is case for two level systems where any desired quantum state can be prepared with high accuracy, allowing them to be used as qubits. Harmonic oscillators, however, have only been prepared in certain types of quantum states. Number states, for example, have remained elusive.
I will demonstrate the generation of number states [1] and arbitrary superpositions of them [2] in a microwave oscillator. We use the precise control over a superconducting phase qubit to transfer microwave photons into the resonator, one at a time [3]. This protocol allows us to create arbitrary quantum states of the photon field, up to approximately 10 photons, limited by decoherence. We analyze the prepared states by mapping out their Wigner function, a full description of the quantum state of a resonator in phase space, equivalent to its density matrix. The figure shows the Wigner function of the state |0> + i|3> + |6>.
[1] Max Hofheinz et al. Nature 454, 310-314 (2008)
[2] Max Hofheinz et al. Nature 459, 546-549 (2009)
[3] C. K. Law and J. H. Eberly, Phys. Rev. Lett. 76, 1055-1058 (1996) -
Study of the Initial Temperature of the Big Bang with the Relativistic Heavy Ion Collider
Guest: Dr. Xiaochun He, Georgia State University, Department of Physics and Astronomy
Thursday, January 27, 2011 4:00 pm - 5:00 pm
Location: Physics 202This talk begins with a brief introduction of the standard model of particle physics and cosmology, which will be followed with a detailed description of the physics motivations and the experimental efforts at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The focus of this talk will be on the recent result from the PHENIX experiment at RHIC and its implication for probing the initial temperature of the matter a few microseconds after the Big Bang.
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From Asteroids to Planets: New Ideas about the Formation of the Solar System
Guest: Dr. Martha Leake, Valdosta State University, Department of Physics, Astronomy, and Geosciences
Thursday, January 20, 2011 4:00 pm - 5:00 pm
Location: Physics 202Using light curve data, one can establish the rotation rate of asteroids—all that’s needed is differential photometry of the asteroid, over one night or several nights. Combining that data with light curves over several apparitions, over several years, and at different phase angles, one can establish the shape and orientation of that “minor planet.” Usually, the triaxial ellipsoid model of an asteroid provides a light curve with two peaks, when the asteroid is broadside to the viewer, and two minima, when the asteroid may be pole on. Of course, there are several variations of this theme, especially if the asteroid has “spots”—producing a similar feature once per complete cycle—or satellites—producing more abrupt decreases as the satellite occults the primary. Variations in orientation, cratering, shadowing, and composition modify the light curve details.
The study of asteroid rotation rates is part of a survey to monitor the spectra of primitive asteroids, C class and subtypes, to search for evidence of water of hydration—or aqueous alteration—and to search for evidence of spectral variations within the rotation cycle. Rotation rate, orientation and aspect ratios would be needed. Typically, C class asteroids lie within the middle to outer part of the main belt, with the more highly altered or even differentiated, asteroid classes S, M and E, occurring closer to the Sun. This convenient and somewhat logical variation may, instead, be a part of complex migration of planets during the formation of the solar system that scatters asteroids both inward and outward from the Jupiter area. Thus, the study of rotation rates correlated with spectra of asteroids may lead to further evidence for the complexity of solar system formation. -
Ultraviolet Photoemission Study of Graphene Crystalline Quality
Guest: Dr. Michael Williams, Clark Atlanta University, Department of Physics
Thursday, January 13, 2011 4:00 pm - 5:00 pm
Location: Physics 202Ultraviolet photoemission spectroscopy is used to investigate the growth of epitaxial graphene layers grown by the thermal decomposition of the Si face of 4H SiC (0001). We find that thinner layers of grown material have more pronounced spectral features in the valence band structure of the material. This result is indicative of a higher ordered surface structure and material quality compared to thicker layers.
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Postponed
Guest: Dr. Inseok Song, University of Georgia, Department of Physics and Astronomy
Thursday, December 2, 2010 4:00 pm - 5:00 pm
Location: Physics 202 -
Geometry of Turbulence: a Stroll Through 61,506 Dimensions
Guest: Dr. Predrag Cvitanovic', Georgia Institute of Technology, School of Physics
Thursday, November 18, 2010 4:00 pm - 5:00 pm
Location: Physics 202In the world of moderate Reynolds number, everyday turbulence of fluids flowing across planes and down pipes a velvet revolution is taking place. Experiments are almost as detailed as the numerical simulations, DNS is yielding exact numerical solutions that one dared not dream about a decade ago, and dynamical systems visualization of turbulent fluid's state space geometry is unexpectedly elegant.
We shall take you on a tour of this newly breached, hitherto inaccessible territory. Mastery of fluid mechanics is no prerequisite, and perhaps a hindrance: the talk is aimed at anyone who had ever wondered why - if no cloud is ever seen twice - we know a cloud when we see one? And how do we turn that into mathematics? -
Light Dosimetry for Photodynamic Therapy
Guest: Dr. Linda Jones, College of Charleston, Department of Physics and Astronomy
Thursday, November 11, 2010 4:00 pm - 5:00 pm
Location: Physics 202Photodynamic therapy is a cancer treatment that combines the effects of oxygen, red light and a photosensitizing dye. The red light is absorbed by dye molecules within the target tissue and the light energy is transferred to molecular oxygen, creating highly reactive oxygen molecules that oxidize tissue components. Clinical results are quite variable because the amount of dye that accumulates in target tissues varies widely between patients. A non-invasive and rapid method to determine the dye content at the time of treatment would allow the light dose to be optimized and may significantly increase the effectiveness of the treatment. I have worked with Herbert Wolfsen, MD (Department of Gastroenterology & Hepatology, Mayo Clinic, Jacksonville) to develop a fluorescence-based method that utilizes a portable fiber optic spectrometer to quantify the Photofrin content in patients undergoing photodynamic therapy for esophageal cancer. I will present an introduction to photodynamic therapy and I will discuss the development of the fluorescence method with clinical results to date.
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Postponed
Guest: Dr. Rodney Canfield, University of Georgia Department of Computer Science
Thursday, November 4, 2010 4:00 pm - 5:00 pm
Location: Physics 202 -
Research Collaboration in Academic Sciences and Engineering: Findings from the National Survey of Academic Scientists
Guest: Dr. Barry Bozeman, UGA, Department of Public Administration and Policy
Thursday, October 21, 2010 4:00 pm - 5:00 pm
Location: Physics 202In three separate NSF-funded studies, Barry Bozeman and his colleagues at University of Georgia and Georgia Tech have been studying the social, behavioral and, now, the ethical aspects of research collaboration. The projects have involved multiple methods, including (1) survey research of a representative sample of science and engineering faculty in U.S. Carnegie Extensive universities (i.e. "Research I), n=2024, (2) data from curricula vitae, and analysis of co-authoring, (3) citations (both articles and patents) data from the SSI/Web of Sciences and (4) interviews. Studies have focused on: (1) numbers of collaborators and characteristics; (2) geographic and social proximity of collaborations, (3) roles of institutions in collaboration (especially university research centers); (4) collaboration and technology transfer between individual scientists and industry (i.e. the Bozeman Industry Involvement Scale); (5) collaboration by type of collaborator, especially graduate students; (6) relationship of collaboration to research productivity; (7) differences between men and women faculty with respect to collaboration patterns and criteria and strategies for developing criteria. The latest phase of the work, just beginning this month, focuses on power dynamics and ethical issues in collaboration, include "ghost authors." After a very brief review of the methods and chief findings of the projects, the presentation will focus on those aspects of collaboration of greatest interest to those attending the presentation.
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Chasing Shadows: Quasar Absorption Lines as Probes of Galaxy Evolution
Guest: Dr. Varsha Kulkarni, University of South Carolina, Department of Physics and Astronomy
Thursday, October 14, 2010 4:00 pm - 5:00 pm
Location: Physics 202The evolution of galaxies and the cosmic history of element production are fundamental themes in modern astrophysics and cosmology. However, the light emitted by distant galaxies is often too faint to allow detailed studies. Fortunately, a very sensitive technique to detect distant galaxies is by means of their "shadows" against the light of bright background sources such as quasars. Absorption lines in quasar spectra can be used to probe interstellar gas in galaxies at various stages of evolution, and thus provide powerful probes of the history of star formation and chemical enrichment in galaxies. Using this technique, we recently uncovered a "missing metals problem'' in low-redshift galaxies, i.e. a discrepancy between the observed amount of metals and the amount predicted by the chemical evolution models. On the other hand, we have recently discovered a new population of galaxies with very high levels of metals, including some that had reached several times the Sun's metallicity 7-10 billion years ago! What are these strange galaxies, and why did they get enriched so quickly? We will discuss clues emerging from our imaging/ spectroscopic observations that promise to shed light on several aspects of galaxy evolution.
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The KEPLER Mission – A Search for Habitable Worlds
Guest: Mr. Roger Hunter, NASA, Ames Research Center
Thursday, October 7, 2010 4:00 pm - 5:00 pm
Location: Physics 202KEPLER is NASA’s first mission capable of finding earth-size worlds around other stars. Launched in March, 2009, KEPLER’s objective is to determine if other Earths exist in our galaxy and how many are there. The results of KEPLER will be profound – either Earth is a very rare planet, or earth-like planets are commonplace. The speaker, Roger Hunter (UGA ’78) is the NASA Project Manager for the KEPLER Mission. He leads a team of over 80 scientists and engineers on a mission that is expected to last at least 3 ½ years in search of another earth. The discussion will provide an overview of the KEPLER mission, its capabilities and characteristics, results to date, and mission expectations.
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From Magnetic Resonance to Molecular Imaging of Biological Systems and Diseases with MRI
Guest: Dr. Hui Mao, Emory University, School of Medicine, Dept of Radiology
Thursday, September 30, 2010 4:00 pm - 5:00 pm
Location: Physics 202The state of the art MRI has become a powerful and primary tool for non-invasive imaging of living systems both in laboratory research and clinical practices. The guidance and applications of physics principles have played critical roles in many aspects of magnetic resonance imaging (MRI), from the discovery of magnetic resonance phenomenon to the development of a library of imaging methods and technology. As MRI becomes a junction of sciences, engineering, biomedical discoveries and clinical applications, we should reflect the impact of physics and look forward to its continuous influences to the development and direction of magnetic resonance imaging field and beyond. With this in mind, I will share with you my laboratory’s current research and experiences in developing MRI methods and applications for diagnostic imaging and medical research. The implementation and applications of diffusion and diffusion tensor imaging to study brain diseases, such as Alzheimer’s disease, will be discussed in the presentation. In addition, I will introduce our work in developing novel magnetic nanoparticles as MR molecular imaging probes for biomarker targeted imaging of cancers as well as some new MRI methods for molecular imaging. Looking into the future, we anticipate that MRI will continue to provide great opportunities for physics to make ground-breaking contributions to biomedical research and discoveries.
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Chiral Symmetry and Medium Modification of Vector Mesons
Guest: Dr. Chaden Djalali, University of South Carolina, Department of Physics and Astronomy
Thursday, September 23, 2010 4:00 pm - 5:00 pm
Location: Physics 202The theory of the strong interaction, Quantum Chromodynamics (QCD), has been remarkably successful in describing high-energy and short-distance-scale experiments involving quarks and gluons. However, applying QCD to low energy and large-distance-scale experiments has been a major challenge. Chiral symmetry is one of the most fundamental symmetries in QCD and provides guiding principles to deal with strong interaction phenomena in the non-perturbative domain. Most of the mass of ordinary matter (98%) is generated by the spontaneous breaking of Chiral symmetry in the vacuum. Various QCD-inspired models predict a modification of the properties of hadrons in nuclear matter from their free-space values. A review of experiments searching for the in-medium modifications of light mesons will be given trying to assess if they confirm or refute these theoretical predictions. Several complementary high statistics experiments are planned at different nuclear physics accelerators (JLab, GSI, JPARC and RHIC) to further study the properties of hadrons in the medium.
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Implementing and Sustaining Curricular Reform in a Large Introductory Physics Course at Georgia Tech
Guest: Dr. Mike Schatz, Georgia Institute of Technology, School of Physics
Thursday, September 16, 2010 4:00 pm - 5:00 pm
Location: Physics 202A novel physics curriculum, Matter and Interactions (M&I), was introduced into Georgia Tech engineering physics courses in Summer 2006; today the curriculum is taught to approximately one thousand students each semester. We will highlight some key issues associated with implementing the M&I curriculum. We will also describe efforts to measure the new curriculum's impact using both standardized assessment tools (concept inventories) and in-depth student interviews (think-aloud protocol studies). The presentation will highlight barriers to implementing and to sustaining reform curricula in university physics courses.
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Quantum computing with Bose--Einstein condensate Bragg interferometry
Guest: Dr. Mark Edwards, Georgia Southern University, Department of Physics
Thursday, September 9, 2010 4:00 pm - 5:00 pm
Location: Physics 202Quantum computers use the interferences of different computational paths to enhance correct outcomes. Quantum computation can be viewed as multi-particle computational interference [1]. I will describe how quantum circuits can be mapped to interferometry experiments performed on Bose-Einstein condensates (BECs) using Bragg pulses. I further describe an extension to an approach, originally developed to prototype Bragg interferometry of BECs [2], to describe new interferometers inspired by quantum information concepts. This approach follows ideas recently introduced in neutron inter- ferometry [3]. Using techniques that have been well calibrated by experiments in con- ventional BEC interferometry [2], experiments associated with some simple quantum circuits using the prototyping method mentioned above are modeled. We prototype ex- tensions to standard Mach-Zehnder configurations, analogous to the four-blade designs of neutron interferometry.
[1] R. Cleve, et al., Proc. R. Soc. Lond. A 454 339 (1998)
[2] J. E. Simsarian, et al., Phys. Rev. Lett. 85, 2040 (2000)
[3] D. A. Pushin, M. Arif, and D. G. Cory, Phys. Rev. A 79, 053635, (2009) -
First Principles Simulations of Piezoelectric Oxides
Guest: Dr. Valentino Cooper, Oak Ridge National Laboratory, Materials Science and Technology Division
Thursday, September 2, 2010 4:00 pm - 5:00 pm
Location: Physics 202Piezoelectrics are dielectric materials which convert electrical energy to mechanical energy (and vice-versa). It is this coupling which makes them crucial to the success of a variety of modern devices including SONAR, ultrasound machines, non-volatile memory devices, and chemical and biological sensors. Given their importance, there has been much research devoted to enhancing the electromechanical responses of these materials. Recent advances in theory, most notably the ability to accurately compute the macroscopic polarization using first principles density functional theory, have opened the door to the computational discovery of new piezeoelectrics. In this presentation, I will demonstrate how concepts and insights gained from first principles calculations can be used to tailor the properties of complex oxides. In particular, I will discuss our use of epitaxial strain through superlattice geometries [1] and chemical composition and ordering [2] to predict structures with enhanced piezoelectric properties.
1. V. R. Cooper and K. M. Rabe, Phys. Rev. B 79 (18), 180101 (2009).
2. S. Takagi, A. Subedi, D. J. Singh and V. R. Cooper, Phys. Rev. B 81 (13), 134106 (2010). -
Quantum Mechanical Calculations for Collision Processes with Atoms, Electrons and Positrons
Guest: Dr. Robert Buenker, Wuppertal Univ., Germany, Department of Chemistry
Thursday, August 26, 2010 4:00 pm - 5:00 pm
Location: Physics 202The quantum mechanical description of inelastic collisions between various types of particles is discussed and illustrated by means of some recent applications. In order to accomplish this goal it is necessary to solve the Schrödinger equation for a collection of atoms to within a satisfactory degree of accuracy. The basic theoretical procedure is to use the Born-Oppenheimer “clamped nuclei” approximation to generate potential surfaces describing the motion of the atoms in a given molecular system. The multireference configuration interaction (MR-CI) method is quite effective for this purpose, since it allows one to compute total energies and wave functions at a high level of accuracy for all types of electronic states over a wide range of nuclear conformations. It has often been employed to describe the potential curves and various coupling elements required for cross section calculations of atom-atom and atom-molecule collision processes. These results are used to solve problems in astrophysics, medicine and semiconductor design, to name a few of the most important applications. A detailed example for the Na(3s,3p)He complex will be discussed in which MR-CI results have been used in a coupled channel treatment of the corresponding inelastic collision processes [C. Y. Lin et al., Phys. Rev. A 78, 052706 (2008)].
Electron scattering requires a different theoretical approach for several reasons. First of all, electrons are too light to be described satisfactorily by the Born- Oppenheimer approximation. In addition, it is necessary to account for the typically metastable nature of the states that result from electron attachment (autoionization processes). This means that the computed energy eigenvalues
must have imaginary components that correspond to the linewidths of the resulting states. A recent example of this type will be discussed which successfully describes vibrational cross section results obtained experimentally for electron collisions with the HCl molecule [M. Honigmann et al., J. Chem. Phys. 133, 044305 (2010)]. Finally, calculations to describe molecular collisions with positrons will be presented. Such processes are also useful in medicine, such as in positron emission tomography (PET). In this case it is necessary to employ wave functions containing many electrons and a lone positron. Computations of annihilation rates and positron affinities for complexes of alkali hydrides and oxides will be used to illustrate this type of theoretical treatment [R. J. Buenker and H.-P. Liebermann, J. Chem. Phys. 131, 114107 (2009). -
Physics and applications of contrast-enhanced MRI - Detection and Evaluation of Tumors Labeled with iron-Oxide Nanoparticles in MRI
Guest: Mr. Jason Langley, UGA, Physics and Astronomy
Thursday, August 19, 2010 4:00 pm - 5:00 pm
Location: Physics 202Contrast agents are used in magnetic resonance imaging (MRI) to enhance contrast difference in tissues by changing relaxation rates between tissues with and without contrast agent. Contrast agents can be broken into two categories: T1–based agents and T2–based agents. T1–based contrast agents change the longitudinal relaxation time (T1) and T2–based contrast agents change the transverse relaxation time (T2). In this talk, we will focus on contrast agents based on super paramagnetic iron oxide (SPIO) nanoparticles. SPIO nanoparticles change T2 of surrounding tissues and are used to label different types of cells. In the talk, methods for detecting labeled cells and quantifying concentrations of labeled cells will be presented.
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The Searle Systems Biology and Bioengineering Undergraduate Research Experience at Vanderbilt University - Equipping Students of all Disciplines For Careers in Post-Reductionist Biology and Medicine
Guest: Dr. Kevin T. Seale
Thursday, April 22, 2010 4:00 pm - 5:00 pm
Location: Rm 201 Physics BuildingDr. Kevin T. Seale from Vanderbilt University is our Undergraduate Awards Day Colloquium Speaker.
Abstract: From its beginning as a descriptive, taxonomic recording of existing species to the recognition of the cell as a fundamental unit of biology to the discovery of the genetic code as the software driver for all living organisms, research in biology and medicine has evolved. Along a timeline similar to the progression of the study of physical sciences from the very large (the solar system and universe) to the very small (subatomic particles), biologists have reached the reductionist limit with the complete description of the structure and function of molecular DNA translation, transcription and replication machinery. Perhaps not surprisingly, biologists, physicists (and engineers, chemists, mathematicians) have met at the bottom of the reductionist path at many universities around the world, and are working together to build models and experiments of ever-greater complexity to study the emergent properties of molecular assemblies such as the biological cell in a growing field known as Systems Biology. Undergraduate students interested in Systems Biology must grapple with the requirement that they declare a major – which by definition will temporarily restrict much of their thinking to existing academic disciplines. The Searle Systems Biology and Bioengineering Undergraduate Research Experience (SyBBURE) at Vanderbilt University is an effort to invigorate the studies of undergraduates of all majors by providing long-term and unfettered access to the Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE) and associated laboratories across campus. Students with active and imaginative minds are encouraged, guided and amply supplied to investigate the function of individual living cells under tightly controlled experimental conditions using state-of-the-art biomicroelectromechanical devices. The SyBBURE undergraduates, along with collaborating faculty are helping to develop and build extensive experimental approaches and apparatus for systems biology research that are more evenly matched to the enormous complexity of a single, living biological cell. I will give an overview of SyBBURE experiments and results and discuss bold new directions chosen by the VIIBRE/SyBBURE cohort to bring the power of modern technology to bear on difficult biological problems.
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A Physicist's Life Cycle
Guest: Joseph Hermanowicz
Thursday, April 8, 2010 4:00 pm - 5:00 pm
Location: 202 PhysicsDr. Robin Shelton is hosting Dr. Joseph Hermanowicz of the University of Georgia Department of Sociology this week. The Abstract for his talk, "A Physicist's Life Cycle" follows.
What can we learn when we follow people over the years and across the course of their professional lives? A sociological study has been undertaken of contemporary academic careers situated in varieties of the modern American university as revealed in the lives of fifty-five university physicists. The study is based on face-to-face interviews with academics who were first interviewed in 1994-95 and again in 2004-05. Physicists were initially sampled across a range of career stages, from early, middle, and late career. The longitudinal study examines the career paths of these academics as they have advanced from these points, including into the stage of retirement and exit from the career. The study examines scientists' shifting perceptions of their jobs to uncover the meanings they invest in their work, when and where they find satisfaction, how they succeed and fail, and how the rhythms of their work change as they age. Interviews with subjects shed light on the ways career goals are and are not met, on the frustrations of the academic profession, and perceptions of the arc of a scientific career.
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On the History of the Recurrence Relations Method and its Application to the Ergodic Hypothesis
Guest: M. Howard Lee
Thursday, April 1, 2010 4:00 pm - 5:00 pm
Location: Physics 202Dr. Bill Dennis will host Dr. M. Howard Lee of the University of Georgia Department of Physics and Astronomy this week. His presentation is entitled "On the History of the Recurrence Relations Method and its Application to the Ergodic Hypothesis."
The recurrence relations method was developed at UGA in the early 1980s. It is an exact analytical formalism designed to study time-dependent or dynamical behavior in many-body systems from first principles. In the ensuing decades the method has been applied to a variety of classical and quantum models of solids, magnets, fluids and plasmas by my students and co-workers at UGA and independently by others elsewhere. Books have been written about it. At this talk the physical idea of this method will be presented.
In the early 2000s this method was first applied to a famous classic problem in statistical mechanics known as the ergodic hypothesis put forth by the great Boltzmann more than a hundred years ago. The hypothesis asserts that time averages are equal to ensemble averages. It has become a foundation of statistical mechanics. But is it really true? If true, why? Most physicists in this field accept or have accepted this hypothesis without knowing answers to such questions. The reason may perhaps be that, until now, there haven't been any tools with which to investigate this weighty problem. How this hypothesis has been unraveled by the recurrence relations method will be presented.
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