Events at Physics |
Events on Tuesday, February 2nd, 2010
- R. G. Herb Condensed Matter Seminar
- Coherent transport in driven optical lattices
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Andrea Alberti, European Laboratory for Non-Linear Spectroscopy
- Abstract: We present a dynamical control of transport of ultra-cold 88Sr atoms loaded in a driven optical lattice. By introducing a modulation of an accelerated lattice potential we induce a controlled coupling between Wannier-Stark states located on different lattice sites. This coupling gives rise to coherent resonant delocalization when the modulation frequency matches the energy separation between adjacent sites, namely the Bloch frequency. We apply this mechanism to engineer a coherent transport over macroscopic distances, and we demonstrate one realization of Loschmidt echos. On the other hand, the same transport mechanism can be applied to micron scale to measure forces with high spatial resolution and ppm sensitivity.
- Host: Saffman
- Chaos & Complex Systems Seminar
- Complex Families: Some Implications of Multiple Partner Fertility for Research and Policy
- Time: 12:05 pm
- Place: 4274 Chamberlin Hall
- Speaker: Marie Cancian, UW-Madison La Folette School of Public Affairs
- Abstract: We most often think of families with children as including a mother, father, and their children in common. However, 40 percent of children are now born to unmarried parents, and recent research suggests that more often than not, one or both of these parents will go on to have children with other partners. The complex families that result-- with siblings, half siblings and step siblings sharing parents and sometimes living quarters-- raise a host of challenges for research and policy. In this seminar I will draw on a series of papers, coauthored with Dan Meyer and other collaborators, to discuss the evolution of complex families and key related policy issues.
- Astronomy Colloquium
- Infrared Astronomy at 45,000 Feet
- Time: 3:30 pm - 5:00 pm
- Place: 3425 Sterling Hall
- Speaker: Pam Marcum, NASA
- Abstract: The joint U.S. and German Stratospheric Observatory for Infrared Astronomy (SOFIA) will be a premier observatory facility during future decades for studying the physics and chemistry of stellar evolution processes. Utilizing the large suite of science instruments and the broad wavelength coverage of SOFIA, astronomers will be armed with unique capabilities to undertake a large breadth of investigations ranging from studies of the Solar System to the star forming history of galaxies over cosmic time. SOFIA is a German-built 2.5-meter telescope mounted in a modified Boeing 747-SP aircraft supplied by NASA. Flying at altitudes as high as 45,000-feet, SOFIA will be above most of atmospheric water vapor that severely limits the ability to do infrared and sub-mm observations using ground-based telescopes. SOFIA's first-generation instruments include broadband imagers, moderate resolution spectrographs capable of resolving broad features due to dust and large molecules, and high resolution spectrometers suitable for kinematic studies of molecular and atomic gas lines at suitable resolution. SOFIA science applications will be discussed, with special emphasis on investigations related to infrared spectroscopy of astrophysical gas, grains and ices. Although the primary impact of SOFIA will be its scientific return, SOFIA's other major advantages include the provision of a platform on which to demonstrate new future technologies and to provide in-flight experience to young scientists, educators and journalists.
- Host: Astronomy Department