Events at Physics |
Events on Thursday, May 9th, 2019
- R. G. Herb Condensed Matter Seminar
- Quantum piezoacoustics: From low-dimensional electrons to qubits
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Johannes Pollanen, Michigan State University
- Abstract: Our research group is working on creating and discovering electronic quantum states of matter in low-dimensional electron systems and controlling tailor-made quantum circuits. I will discuss our work developing hybrid piezoacoustic devices for coupling high frequency microwaves to two-dimensional electron systems. In particular I will highlight our recent results demonstrating in situ gate-tunable acoustoelectric transport in exfoliated monolayer graphene by measuring the voltage created as high-frequency surface acoustic waves dynamically drive charge carriers in the graphene. We employ a flip-chip device configuration to conduct these acoustoelectric measurements while simultaneously controlling the graphene carrier density with a metal-oxide back-gate. I will also describe our efforts to couple this hybrid piezoacoustic devices to superconducting circuit based quantum bits and to a unique low-dimensional electron system formed by trapping an ensemble of electrons in vacuum above the free surface of superfluid helium.
- Host: Robert McDermott
- Cosmology Journal Club
- Time: 12:00 pm - 1:00 pm
- Place: 5242 Chamberlin Hall
- Abstract: Please visit the following link for more details:
http://cmb.physics.wisc.edu/journal/index.html
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 Ross Cawthon (cawthon@wisc.edu) and Santanu Das (sdas33@wisc.edu). - Astronomy Colloquium
- Planets in a bottle: Exploring planetary atmospheres in the lab
- Time: 3:30 pm - 5:15 pm
- Place: 4421 Sterling Hall, Coffee and cookies 3:30 PM, Talk begins 3:45 PM
- Speaker: Sarah Horst, The Johns Hopkins University
- Abstract: From exoplanets, with their surprising lack of spectral features, to Titan and its characteristic haze layer, numerous planetary atmospheres may possess photochemically produced particles of "haze". With few exceptions, we lack strong observational constraints (in situ or remote sensing) on the size, shape, density, and composition of these particles. Photochemical models, which can generally explain the observed abundances of smaller, gas phase molecules, are not well suited for investigations of much larger, solid phase particles. Laboratory investigations of haze formation in planetary atmospheres therefore play a key role in improving our understanding of the formation and composition of haze particles. I will discuss a series of experiments aimed at improving our understanding of the physical and chemical properties of planetary atmospheric hazes on Titan, Pluto, super-Earths, and mini-Neptunes.