Events at Physics |
Events During the Week of February 15th through February 22nd, 2015
Monday, February 16th, 2015
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Development of Innovative Wall and Divertor Plasma-Facing Components for Magnetically-Confined 3D Plasmas
- Time: 12:00 pm - 1:00 pm
- Place: 1610 Engineering Hall
- Speaker: Prof. Davide Curreli, Univ of Illinois at Champagne-Urbana
- Council Meeting
- CANCELED
- Time: 4:00 pm
- Place: 2314 Chamberlin (Chair's Conference Room)
- R. G. Herb Condensed Matter Seminar
- Faculty Candidate Seminar
- Custom low-dimensional material systems explored from atom to bulk
- Time: 5:00 pm - 6:00 pm
- Place: 5280 Chamberlin
- Speaker: Adina Luican-Mayer, Argonne National Lab, Center for Nanoscale Materials
- Abstract: The ability to controllably layer atomically thin crystals into custom-made materials holds promise for realizing physical systems with distinct properties, previously inaccessible. The experimental results described in this talk seek to uncover the unique nature of the charge carriers in such few-atoms-thick materials as well as effects that interlayer coupling and disorder have on their properties. Firstly, I will discuss scanning tunneling microscopy (STM) and spectroscopy (STS) experiments performed on graphene systems at low temperatures and in magnetic field. These techniques give access, down to atomic scales, to structural information as well as to the density of states. We find that twisting graphene layers away from the equilibrium Bernal stacking leads to the formation of Moiré patterns and results in a system with novel electronic properties tuned by the twist angle. Moreover, we study Landau quantization in graphene and its dependence on charge carrier density. Performing spatially resolved STM/STS we demonstrate the true discrete quantum mechanical electronic spectrum within the Landau level band near an impurity in graphene in the quantum Hall regime. Secondly, I will discuss temperature-dependent Raman spectroscopy measurements that demonstrate how the number of layers in a crystal of 1T-TaS2 determines the different types of charge density order in this material.
- Host: Coppersmith
Tuesday, February 17th, 2015
- Chaos & Complex Systems Seminar
- The limits to growth or the limits to models?
- Time: 12:05 pm - 1:00 pm
- Place: 4274 Chamberlin Hall (Refreshments will be served)
- Speaker: Jim Blair, Milton and Edgewood College
- Abstract: Thomas Malthus and the Malthusian Trap
The Limits to Growth in 3 iterations (Club of Rome)
The Limits to the Limits to Growth (Ben Bova)
The Bet: Paul Ehrlich vs Julian Simon
2020 Vision (1970), and at the Midway (1995) - Host: Clint Sprott
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Faculty Candidate Seminar
- Using kaons to unlock the secrets of the neutrino
- Time: 4:00 pm - 5:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Joshua Spitz, MIT
- Abstract: More than 80 years after its proposed existence, the neutrino remains
largely mysterious and elusive. Despite this fact, we are closing in
on answers to some of the big questions surrounding the "little
neutral one". After an introduction to the neutrino and neutrino mass,
I will discuss two of the most important open questions in particle
physics and cosmology today: (1) How many neutrinos are there? and (2)
Is there a difference between matter neutrinos and antimatter
neutrinos?
When a charged-kaon decays at rest, it usually produces a
monoenergetic (236 MeV) muon neutrino. Recently, this unique neutrino has been
identified as an important tool in helping to eventually answer these
big questions. I will discuss the "kaon decay-at-rest" concept for
neutrino physics and present a set of experiments that will be able to
perform the relevant measurements in the next few years. - Host: Dasu
Wednesday, February 18th, 2015
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Faculty Candidate Seminar
- Measuring the Neutrino Mass with Tritium Beta Decays
- Time: 8:30 am - 9:30 am
- Place: 4274 Chamberlin Hall
- Speaker: Noah Oblath, MIT
- Abstract: Neutrinos are the most common matter particles in the universe, and yet many fundamental questions about them remain unanswered. They are a crit- ical part of our understanding of everything from cosmology and astrophysics to nuclear reactors and particle accelerators. The absolute neutrino mass scale is one of those unanswered questions, and the most sensitive direct measure- ments of it are made by tritium beta-decay experiments. I will discuss two such experiments: the Karlsruhe Tritium Neutrino Experiment (KATRIN), and Project 8. The KATRIN experiment will use a large electromagnetic spectrometer to improve the sensitivity to the neutrino mass scale by an order of magnitude over the previous generation of tritium beta-decay experiments. The Project 8 experiment will allow us to further improve the sensitivity to the neutrino mass using a novel technique: measuring the frequency of the cyclotron radiation emitted by beta-decay electrons as they travel in a mag- netic field. I will describe these experimental efforts, including recent results from Project 8, and discuss how, over the next several years, they will both contribute to our knowledge of the properties of neutrinos and their role in the universe.
- Host: Dasu
- Department Meeting
- Time: 12:15 pm
- Place: 5310 Chamberlin Hall
- R. G. Herb Condensed Matter Seminar
- Faculty Candidate Seminar
- Spin-charge scattering in Luttinger Liquids
- Time: 4:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Alex Levchenko
- Abstract: I will discuss the violation of spin-charge separation in generic Luttinger liquids and investigate its effect on the relaxation, thermal and electrical transport of genuine spin-1/2 electron liquids in ballistic quantum wires. We will identify basic scattering processes compatible with the symmetry of the problem and conservation laws that lead to the decay of plasmons into the spin modes and also discuss Brownian backscattering of spin excitations. I will present a closed set of coupled kinetic equations for the spin-charge excitations and solve the problem of electrical and thermal conductance of interacting electrons for an arbitrary relation between the quantum wire length and spin-charge thermalization length.
- Host: Coppersmith
Thursday, February 19th, 2015
- No events scheduled
Friday, February 20th, 2015
- Cosmology Journal Club
- An Informal discussion about a broad variety of arXiv papers related to Cosmology
- Time: 12:15 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