Events at Physics |
Events During the Week of December 1st through December 8th, 2013
Monday, December 2nd, 2013
- Cosmology Journal Club
- An Informal discussion about a broad variety of arXiv papers related to Cosmology
- Time: 12:30 pm
- Place: 5242 Chamberlin Hall
- Abstract: Please visit the following link for more details:
http://cmb.physics.wisc.edu/journal/index.html
Please feel free to bring your lunch!
If you have questions or comments about this journal club, would like to propose a topic or volunteer to introduce a paper, please email Le Zhang (lzhang263@wisc.edu) - Host: Peter Timbie
Tuesday, December 3rd, 2013
- Chaos & Complex Systems Seminar
- What happens when policy comes before science?
- Time: 12:05 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Sherry Tanumihardjo, UW Department of Nutritional Sciences
- Abstract: Vitamin A is essential for multiple functions in mammals. Without vitamin A, mammals cannot grow, reproduce, or fight off disease. Because of its numerous functions in humans, biomarkers of vitamin A status are quite diverse. Assessment of liver reserves of vitamin A is considered the gold standard because the liver is the major storage organ. However, this measure is not feasible in human studies. Alternative biomarkers of status can be classified as biological, functional, histologic, and biochemical. Before overt clinical damage to the eye, individuals who suffer from vitamin A deficiency are plagued by night blindness and longer vision-restoration times. These types of assessments require large population-based evaluations. Therefore, surrogate biochemical measures of vitamin A status, as defined by liver reserves, have been developed. Serum retinol concentrations are a common method used to evaluate vitamin A deficiency. Often policy is set based on serum retinol concentrations. However, they often do not respond to interventions and do not decline until liver reserves are severely depleted. Therefore, surrogate measures of liver reserves were developed, which include stable isotope and relative dose response tests.
- Host: Clint Sprott
- Atomic Physics Seminar
- Quantum Spin Ice with Rydberg dressed atoms
- Time: 2:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Alexander Glaetzle, University of Innsbruck
- Abstract: We will present a discussion of quantum spin ice, which represents a paradigmatic example on how the physics of frustrated magnets is related to gauge theories. The goal is to assemble a system of cold Rydberg atoms and to design interactions that realize a toy model of quantum spin ice on a two-dimensional checkerboard lattice. In particular, we exploit the strong angular dependence of Van-der-Waals interactions between high angular momentum Rydberg states. Together with the possibility of designing step-like potentials using ground state atoms weakly dressed by Rydberg states, we can implement Abelian gauge theories in a series of geometries, which could be demonstrated within state of the art experiments.
- Host: Mark Saffman
- Atomic Physics Seminar
- A hybrid Rydberg atom-superconductor quantum interface
- Time: 2:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Jonathan Pritchard, UW Madison
- Abstract: We propose a quantum interface for creating hybrid entanglement between neutral atom and superconducting qubits. The interface is mediated by coupling superconducting qubits to microwaves, and microwaves to Rydberg excited single atoms. Fidelity calculations based on realistic parameters for an atom located close to a CPW microwave resonator, and a progress report on experimental implementation will be presented.
- Host: Mark Saffman
Wednesday, December 4th, 2013
- Career Talk
- SHINE Medical Technologies
- Time: 3:30 pm
- Place: 2103 Chamberlin Hall
- Speaker: Greg Piefer, CEO, SHINE Medical Technologies
Thursday, December 5th, 2013
- R. G. Herb Condensed Matter Seminar
- Non-equilibirum Dynamics with Cold Polar Molecules: Glasses and the Hexatic Phase
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Dr. Wolfgang Lechner, University of Innsbruck
- Abstract: The realization of cold ensembles of polar molecules has opened a new pathway to explore the dynamics of quantum many body systems with strong, long-range and anisotropic dipolar interactions. While theoretical studies have so far focused on the equilibrium phases in the highly degenerate quantum regime , I will focus in my talk on non-equilibirum dynamics in the regime where quantum and thermal fluctuations are of the same order of magnitude. I will present two proposals: i.) a study on the glass transition in the presence of quantum fluctuations and ii.) a study on quantum fluctuations in the hexatic phase. i.) I will show, how the glass phase can be prepared in a bilayer system of ultracold dipolar molecules and present results on classical and quantum glassy behavior, characterized by long tails in the relaxation time and dynamical heterogeneity. I will also present experimental accessible order parameters based on marker molecules, distinguished by properly chosen internal levels, and find quantum features of dynamical heterogeneity. ii.) The hexatic phase is an intermediate phase in two dimensional systems when going from the crystal to the liquid phase. I will present results on the influence of quantum fluctuations on the nature of the hexatic phase and methods that allow one to measure these effects in a setup with polar molecules.
- Host: Chubukov, Saffman & Yavuz
- Astronomy Colloquium
- “Star Formation, Solar Physics, and Stellar Astrophysics: A Data-Intensive Approachâ€
- Time: 3:30 pm - 5:00 pm
- Place: 4421 Sterling Hall
- Speaker: Keivan Stassun, Vanderbuilt University
- Abstract: Large time-domain surveys, from the ground and from space, are enabling new data-intensive approaches to a variety of problems in stellar and solar astrophysics. This talk describes four projects, each serving as a vignette of a different but complementary mode of data-intensive research into the<br>
formation and evolution of Sun-like stars. The SLoWPoKES project extracts from the Sloan Digital Sky Survey the largest sample of wide low-mass binaries ever assembled, which we use to constrain binary star formation theory and the role of third bodies in the formation of tight binaries. The EB Factory project seeks to identify rare, but astrophysically very interesting, case studies from among the large numbers of eclipsing binaries being harvested by surveys for transiting exoplanets. We use a set of rare low-mass and brown-dwarf eclipsing binaries to elucidate the role of magnetic activity in altering the basic properties of low-mass stars and brown dwarfs, affecting our understanding of the stellar initial mass function and the frequency of brown dwarfs in stellar populations. The X10000 Project studies the structures of young stellar coronae in order to understand the role of extreme coronal mass ejections in the angular momentum evolution of young stars. As a by-product of this work, we have determined the first robust empirical relationship between X-ray flare energy and coronal mass loss for the Sun. Finally, we use the Kepler database of precision light curves for 150,000 stars to present a new, a Eurooephotometric variability HR diagrama Euro which enables accurate determination of stellar surface gravities, improves our knowledge of exoplanet properties, and enhances our ability to identify the most radial-velocity quiet stars for exoplanet discovery. - Host: Prof Emeritus Ed Churchwell/Barb Whitney
Friday, December 6th, 2013
- Theory Seminar (High Energy/Cosmology)
- CANCELLED - TO BE RESCHEDULED
- Title to be announced
- Time: 2:00 pm
- Place: 5280 Chamberlin Hall
- Speaker: Devin Walker, SLAC
- Theory Seminar (High Energy/Cosmology)
- The dark 3+1+1 model
- Time: 2:00 pm
- Place: 5280 Chamberlin Hall
- Speaker: Jinrui Huang, Los Alamos National Lab
- Abstract: The existence of light sterile neutrinos in the eV mass range with relatively large mixing angles with the active neutrinos has been proposed for a variety of reasons, including to improve the fit to the LSND and MiniBooNE neutrino oscillation experiments, and reactor disappearance experiments. It was shown that neutrino mixing with a heavier sterile neutrino, in the mass range between 33 eV and several GeV, could significantly affect and improve the agreement between neutrino oscillation models with light sterile neutrinos and short baseline experimental results, allowing for a new source of CP violation in appearance experiments and for different apparent mixing angles in appearance and disappearance experiments. However various collider experiment, supernovae, and cosmological constraints can eliminate most of the parameter region where such a heavy sterile neutrino can have a significant effect on neutrino oscillations. I will present a model allowing a new light scalar in the MeV mass region, which is a potential dark matter candidate, to interact with the sterile neutrinos. The model can satisfy all experimental constraints and is a consistent theory of neutrino oscillation anomalies and dark matter which can also potentially explain the INTEGRAL excess of 511 keV gamma rays in the central region of the galaxy.
- Physics Department Colloquium
- New Frontiers of Quantum Simulations with Atoms and Ions
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall (coffee at 4:30 pm)
- Speaker: Prof. Dr. Peter Zoller, Institut für Theoretische Physik, Universität Innsbruck, University of Innsbruck
- Abstract: Recently, the condensed matter and atomic physics communities have mutually benefited from synergies emerging from the quantum simulation of strongly correlated systems using atomic setups. In the first part of the talk we give an overview of analog and digital quantum simulation with cold atoms in optical lattices and trapped ions. In the second part we discuss possible future directions: while there is presently significant interest in artificial gauge fields mimicking magnetic fields in (neutral) atom setups to observe phenomena like fractional quantum Hall physics, we will discuss prospects of realizing simple models of dynamical gauge fields (lattice gauge theories) as a next generation of possible cold atom experiments, where the (very long term) vision is to perform quantum simulation of lattice gauge theories of QED and QCD.
- Host: Mark Saffman