Events at Physics |
Events During the Week of January 15th through January 22nd, 2017
Monday, January 16th, 2017
- No events scheduled
Tuesday, January 17th, 2017
- Atomic Physics Seminar
- Quantum Control of Ultracold Dipolar Molecules
- Time: 12:00 pm
- Place: 5280 Chamberlin Hall
- Speaker: Huanqian Loh, MIT
- Abstract: Polar molecules offer long-range anisotropic interactions, which are fundamental to a wide variety of phenomena, from ferrofluid behavior to the folding of proteins. Recent demonstrations of cooling and trapping polar molecules have made it possible to study these particles in the quantum regime, making them highly attractive for applications such as quantum information storage and exploring novel condensed matter phases. In this talk, I will report on the quantum control of dipolar fermionic NaK molecules, which we have synthesized in the ground state at ultracold temperatures as low as 300 nK. Using microwaves, we have coherently manipulated not only the rotational states of the molecules, but also the nuclear spin degree of freedom. I will present our observation of nuclear spin coherence times on the scale of 1 second, and discuss its implications for quantum memory and probing new physics via Hertz-level precision spectroscopy.
- Host: Thad Walker
- Chaos & Complex Systems Seminar
- How worried should we be about congenital Zika virus?
- Time: 12:05 pm - 1:00 pm
- Place: 4274 Chamberlin
- Speaker: Dave O'Connor, UW Department of Pathology and Laboratory Medicine
- Abstract: I will talk about Zika as an example of what happens when a new virus that we know little about emerges, discuss what we've learned about Zika, and then talk about what factors might govern the emergence of such viruses that could threaten human health in the future.
- Host: Clint Sprott
- Theory Seminar (High Energy/Cosmology)
- The Fate of Axion Stars
- Time: 3:30 pm
- Place: 5280 Chamberlin
- Speaker: Hong Zhang, Ohio State
- Abstract: If the dark matter consists of axions, some of it will condense into axion stars, which are gravitationally bound Bose-Einstein condensates of axions. If an axion star accretes enough axions to exceed a critical mass, it will collapse. The fate of a collapsing axion star has not been established. One possibility for the remnant is a much denser axion star in which the attractive forces of gravity and axion pair interactions are balanced by the mean-field pressure of the axion Bose-Einstein condensate. A nonrelativistic effective field theory for axions can provide insights into the fate of axion stars. The collapsing process of axion stars and the possible denser remnant produce unique monochromatic radio-frequency signals at odd-integer harmonics of the fundamental frequency set by the axion mass.
- Host: Josh Berger
Wednesday, January 18th, 2017
- No events scheduled
Thursday, January 19th, 2017
- R. G. Herb Condensed Matter Seminar
- Physics / Electrical and Computer Engineering
- Physics after the lab and the desk: Your work in PRL
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Samindranath Mitra , Editor in Physical Review Letters
- Abstract: Physics research takes place mostly at your desk, at the keyboard, in the lab. You communicate results through posters, talks, and papers -- leading to, hopefully, wide dissemination and recognition. The sequence entails interacting with journal editors, referees, conference chairs, journalists, and so on. I will focus on this post-research collaborative process in physics, primarily through the lens that is Physical Review Letters.<br>
- Host: Mark Eriksson and Irena Knezevic
- Atomic Physics Seminar
- Quantum entanglement for precision sensing with atoms and light
- Time: 12:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Onur Hosten, stanford
- Abstract: In the last decades, advances in the level of precision in controlling atomic and optical systems opened up the low-energy precision frontier to fundamental physics tests in addition to yielding new applied sensing technologies. In this talk I will focus on our experiments with cold atoms highlighting some of the most recent developments in the prospect of using quantum entanglement to further improve the precision of atomic and optical sensors.
I will describe the generation of 20dB spin-squeezed states of half a million 87Rb atoms inside of an optical cavity. From a practical point of view, the generated states enable up to a 100-fold reduction in required averaging times or atom numbers to achieve a given precision. I will explain the implementation of an atomic clock operating 10 dB beyond the standard quantum limit as well as the investigations of entanglement and Bell correlations in this system. I will then describe the demonstration of a new concept we call quantum phase magnification which utilizes optical cavity-aided interactions between atoms to magnify signals to-be-measured. This technique eliminates the need for low noise detection to achieve phase sensitivities beyond the standard quantum limit. I will conclude with future visions. - Host: Thad Walker
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Cosmic-ray proton measurements with the Fermi-LAT
- Time: 2:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: David Green, University of Maryland/Goddard
- Abstract: The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope has continuously observed the gamma-ray sky since June 2008.
Cosmic-ray protons represent the majority of events downloaded from the Fermi-LAT, which are removed from the gamma-ray dataset. Our sample is comprised of over 1 billion cosmic-ray protons to TeV energies. We present the measurement of the cosmic-ray proton spectrum between 54 GeV and 9.5 TeV using 7 years of Pass 8 flight data from the Fermi-LAT. We developed a dedicated proton event selection with an acceptance of 0.25 m^2 sr. Our analysis yields a large dataset with low statistical uncertainty and low residual contamination for a spectral measurement. The systematic errors associated with the acceptance, energy measurement, GEANT4 Monte-Carlo simulations are an order of magnitude larger than the statistical uncertainty. The event selection and spectral measurement of the proton analysis create the opportunity for additional proton analyses with the Fermi-LAT, such as a dedicated proton anisotropy search. - Host: Stefan Westerhoff
Friday, January 20th, 2017
- Physics Department Colloquium
- Very-high-energy gamma-ray astrophysics with HAWC
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall
- Speaker: Ignacio Taboada, Georgia Tech
- Abstract: HAWC is a second generation ground detector searching for in TeV gamma-rays. HAWC is special because of its instantaneous very wide field of view (2 steradians, similar to a human eye) and because it operated continuously. This makes HAWC an ideal survey detector and complements point/dark time only operation of more sensitive air Cherenkov telescopes such as VERITAS. In its first 17 month of operation HAWC has detected ~40 sources, mostly in our own galaxy, including pulsar wind nebula, supernova remnants, unidentified objects, etc. In this colloquium I’ll discuss initial HAWC results as well as a search for counterpart TeV gamma-ray objects responsible for IceCube’s neutrinos.
- Host: Westerhoff
