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January 24, 2020

Physics Colloquium

Date: Thursday, January 30, 2020

Speaker: Swapan Chattopadhyay, Fermilab and Northern Illinois University

Title: Particle Accelerator and Emerging Quantum Initiatives at Fermilab

Abstract: Fermilab is building a state-of-the-art high current proton accelerator complex PIP-II in support of DUNE (Deep Underground Neutrino Experiment), its international flagship particle physics experiment, while advancing fundamental accelerator R&D of nonlinear dynamics, high current proton beams, and single electron quantum dynamics in its experimental test accelerator complex FAST/IOTA.

Synergistically, as part of a national DOE ‘Quantum Initiative’, Fermilab is hosting half a dozen funded R&D activities in the science and technology of Quantum Sensors via its emerging strong Quantum Science and Technology Program, including superconducting cavity-based dark matter ‘Axion’ search and prototype 50-qubit quantum computer, quantum algorithms for high energy experimental physics and a 100-meter long-baseline atomic beam interferometer to demonstrate macroscopic atomic quantum entanglement and as a quantum sensor for the dark sector and stochastic cosmic gravitational wave background from the early universe.

I will give a flavor and description of some of these current activities at Fermilab.

Host: Jim Brau

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January 17, 2020

Physics Colloquium

Date: Thursday, January 23, 2020

Speaker: Mike Raymer, UO Physics Dept.

Title: The National Quantum Initiative, or Mr. Raymer goes to Washington

Abstract:

The National Quantum Initiative Act, which passed with strong bipartisan support in Congress and was signed into law by President Trump in late 2018, authorizes up to $1.275B in federal funding over five years and instructs the NIST, NSF, and DOE to work with academic institutions and private industry to catalyze the growth of quantum information science and technology (QIST). What are the main goals, opportunities, and hoped-for outcomes of QIST? What is the state of the art? How did a professor from the UO happen to initiate and organize the lobbying effort that led to passage of the NQI Act? How did Ivanka Trump assist in the process? The answers to some of these questions (without spoilers) can be found in the article:

“The US National Quantum Initiative – from Act to Action,” Christopher Monroe, Michael G Raymer and Jacob Taylor, Science, 3 May 2019, VOL 364 ISSUE 6439

https://iopscience.iop.org/article/10.1088/2058-9565/ab0441/meta

Host: Dave Wineland

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January 10, 2020

Physics Colloquium

Date: Thursday, January 16th, 2020

Speaker: Nick Hutzler, Caltech

Title: Searching for new particles and forces using polyatomic molecules

Abstract: The fact that the universe is made entirely out of matter, and contains no free anti-matter, has no physical explanation.  While we cannot currently say what process created the matter in the universe, we know that it must violate a number of fundamental symmetries, including those that forbid the existence of certain electromagnetic moments of fundamental particles.  We can search for signatures of these electromagnetic moments via precision measurements in polar molecules, whose extremely large internal electromagnetic fields can significantly amplify these moments.  These effects would arise from physics beyond the Standard Model, which enables tabletop searches for new, symmetry-violating particles and forces.  With
modern, quantum science techniques to control polar molecules, these searches can currently reach into the TeV scale, and offer many routes to even higher scales.  In this talk, I will discuss our lab’s approach to performing these tabletop measurements with polyatomic molecules, whose complex structure offers a unique opportunity to
combine robust precision measurement techniques with laser cooling and trapping.  This allows us to build experiments with sensitivity to a variety of new physics sectors, and a route to exploring the PeV scale.

Host: Laura Jeanty

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January 3, 2020

Physics Colloquium

Date: Thursday, January 9th, 2020
Speaker: Nathan Wiebe, UW and Pacific Northwest National Labs

Title: Using machine learning to learn magnetic fields with NV centers at room temperature

Abstract: Nitrogen-vacancy (NV) centers in diamond are appealing nanoscale quantum sensors for temperature, strain, electric fields, and, most notably, magnetic fields. However, the cryogenic temperatures required for low-noise single-shot readout that have enabled the most sensitive NV magnetometry reported to date are impractical for key applications, e.g., biological sensing. Overcoming the noisy readout at room temperature has until now demanded the repeated collection of fluorescent photons, which increases the time cost of the procedure, thus reducing its sensitivity. Here, we show how machine learning can process the noisy readout of a single NV center at room temperature, requiring on average only one photon per algorithm step, to sense magnetic-field strength with a precision comparable to those reported for cryogenic experiments. Analyzing large datasets from NV centers in bulk diamond, we report absolute sensitivities of 60  nT s1/2 including initialization, readout, and computational overheads. We show that machine learning techniques, such as sequential Monte-Carlo methods, allow dephasing times to be estimated simultaneously to the magnetic field and that time-dependent fields can be dynamically tracked at room temperature. Our results dramatically increase the practicality of early-term single-spin sensors.

Host: Steven van Enk

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December 6, 2019

Physics Colloquium Series

The Physics Colloquium series will resume on Thursday, January 9th, 2020.

Happy Holidays! Wishing you a beautiful holiday season and a new year of peace and happiness!

 

December 2, 2019

Physics Colloquium Series

Date: Thursday, December 5th, 2019

Speaker: Luca Mazzucato, UO Biology Dept.

Title: The role of time in neural circuits and behavior

Abstract:  Spontaneous behavior in animals and humans shows a striking amount of variability both in the spatial domain (which actions to choose) and temporal domain (when to act). Concatenating actions into sequences and behavioral plans reveals the existence of a hierarchy of timescales ranging from hundreds of milliseconds to minutes. How does such a complex spatiotemporal structure emerge from neural circuits dynamics? In this talk, we will present recent results from experiments and theory suggesting a new computational mechanism generating the temporal variability underlying naturalistic behavior. We will show how neural activity from the secondary motor cortex of rats unfolds through temporal sequences of attractors, which predict the intention to act. These sequences naturally emerge from recurrent cortical networks, and correlations play a crucial role in explaining the variability in action timing. We will then discuss how processing time in these recurrent circuits can be accelerated or slowed down via neuromodulation or perturbation. Finally, we will borrow ideas from spin glasses to speculate on the origin of the observed hierarchies of timescales.

Location: Room 100, Willamette hall

Host: Jayson Paulose

Please join us for a catered reception at 3:40pm in the Paul Olum, Willamette Hall Atrium.

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November 22, 2019

Physics Colloquium Series

The Physics colloquium series will resume on Thursday, December 5th.

Happy Thanksgiving!

 

 

November 15, 2019

Physics Colloquium Series

Date: Thursday, November 21, 2019

Speaker: Keat Ghee Ong, UO, Phil and Penny Knight Campus for Accelerating Scientific Impact

Title: Embedded Wireless Sensors

Abstract:  Embedded wireless sensors are self-powered or passively powered sensors residing inside or around the object/area of interest for real-time, localized information gathering. Physical, chemical, and/or biological data collected from these sensors are usually wirelessly transmitted to a centralized system for further processing and interpretation. Embedded wireless sensors have many applications such as continuous structural monitoring, human health monitoring, pollution detection and home security, etc. Since different types of sensors can be incorporated into various objects and environments, embedded sensors are not limited to a single class of sensor or a specific measurement technique. The speaker has 20 years of experience in embedded sensors technologies, and has developed a number of them including the RFID sensors, the magnetoelastic sensors, and the battery-powered wireless Bluetooth sensors. Currently, his lab focuses on the implementation of these sensors for regenerative medicine and environmental monitoring.

This presentation will focus on the design and application of embedded wireless sensors for medical applications. Specifically, the application of magnetoelastic sensors, RFID sensors, and Bluetooth-based sensors to provide real-time monitoring of bones and blood vessels will be presented. The speaker will also describe the use of magnetoelastic sensors for detecting biomarkers and other chemical concentrations. Furthermore, the strengths and weaknesses of embedded sensors, as well as their future prospects and challenges, will be discussed.

Location: Room 100, Willamette hall

Host: Richard Taylor

Please join us for a catered reception at 3:40pm in the Paul Olum, Willamette Hall Atrium.

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November 11, 2019

Physics Colloquium Series

Date: Thursday, November 14, 2019

Speaker: Tim Gardner, UO, Knight Campus for Accelerating Scientific Impact

Title: Tracking Neural Programs for Song

Abstract: We seek to understand the neural circuit basis for memory stability in the songbird. This talk describes technical challenges to recording neural activity in singing birds, and engineering efforts to provide miniature devices for brain and nerve recording. We apply these tools to ask how the brain encodes a stable behavior – the stereotyped song of a zebra finch. We find a mesoscopic dynamical pattern that relates excitatory and inhibitory neurons, state dependent control of variability in neural firing patterns, and an unexpected turnover in the neural representation of a stable behavior that occurs during intervals of sleep. These observations can be loosely related to aspects of regularization in modern machine learning  that reduce over-fitting of artificial neural networks.

Location: Room 100, Willamette hall

Host: Raghu Parthasarathy

Please join us for a catered reception at 3:40pm in the Paul Olum, Willamette Hall Atrium.

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November 1, 2019

Physics Colloquium Series

Date: Thursday, November 7, 2019

Speaker: Zoltan Ligeti, Lawrence Berkeley National Laboratory

Title: Flavor Physics: Past, Present, Future

Abstract: Despite its spectacular successes, the standard model of particle physics does not contain a possible candidate for dark matter, nor can it explain the observed asymmetry between matter and antimatter in the Universe.

The interactions of the Higgs boson, which give quarks and leptons their masses, also lead to violation of the symmetry between matter and antimatter in electroweak interactions.  This can explain the differences observed between matter and antimatter in laboratory experiments, but it is insufficient to explain the dominance of matter over antimatter in the Universe.  Thus, additional interactions must exist, which differentiate between matter and antimatter.  The Large Hadron Collider will test the properties of the Higgs boson with ever increasing precision.  After a brief review of the standard model, I discuss some of the current constraints on extensions of the standard model, what we may learn in the next decade, and how this information could be combined with possible other discoveries to answer some deep questions.

Location: Room 100, Willamette hall

Host: Graham Kribs

Please join us for a catered reception at 3:40pm in the Paul Olum, Willamette Hall Atrium.

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