Events at Physics |
Events During the Week of January 19th through January 26th, 2020
Monday, January 20th, 2020
- No events scheduled
Tuesday, January 21st, 2020
- Chaos & Complex Systems Seminar
- Color: Physics and perception
- Time: 12:05 pm - 1:00 pm
- Place: 4274 Chamberlin (refreshments will be served)
- Speaker: Pupa Gilbert, UW Department of Physics
- Abstract: Unless we are colorblind or are in the dark, as soon as we look at any object, we know what color the object is. Simple, isn’t it? No, not really. The color we see is rarely just determined by the physical color, that is, the wavelength of visible light associated with that color. Other factors, such as the illuminating light, or the brightness surrounding a certain color, affect our perception of that color. Most striking, and useful, is understanding how the retina and the brain work together to interpret the color we see, and how they can be fooled by additive color mixing, which makes it possible to have color screens and displays. I will show the physical origin of all these phenomena and give live demos as I explain how they work. Bring your own eyes!
For more information: (1) watch TED talk: “Color: Physics and Perception” and (2) read book: PUPA Gilbert and W Haeberli “Physics in the Arts”, ISBN 9780123918789. - Host: Clint Sprott
Wednesday, January 22nd, 2020
- No events scheduled
Thursday, January 23rd, 2020
- R. G. Herb Condensed Matter Seminar
- Tunable Excitonic Ground States in Double Layer Graphene
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Yihang Zeng, Columbia University
- Abstract: Two-component quantum Hall systems, such as double layer graphene (DLG) separated by a tunnel barrier, have been demonstrated to host ground states of indirect interlayer exciton when the lowest Landau level (LL) in each layer is half filled. Upon decreasing the temperature, the system will condense into a macroscopically ordered state with quasi long-range phase coherence, termed exciton condensate, a superfluid of exciton. We realized the crossover between exciton condensate with strong coupling and weak coupling by changing the exciton density. Upon unbalancing the density in each layer, we observe a sharp transition from an exciton superfluid to an exciton insulator, insulating in both charge transport and exciton transport measurement, which is interpreted as a Wigner crystal of exciton pinned by disorder. With tunable Bohr radius and exciton-exciton distance, we for the first time show the entire phase diagram of the excitonic ground states in the lowest LL in DLG.
- Host: Alex Levchenko
- Cosmology Journal Club
- Time: 12:00 pm - 1:00 pm
- Place: 5242 Chamberlin Hall
- Abstract: http://cmb.physics.wisc.edu/journal/index.html
We discuss papers from arxiv.org related to cosmology each week. All are welcome and feel free to bring your lunch. If there is a paper you would like to present, or have questions or comments, please email Ross Cawthon (cawthon@wisc.edu) and Santanu Das (sdas33@wisc.edu). Friday, January 24th, 2020
- No events scheduled