Host: Xinyu Dai
Title: "Strong Observational Constraints on the Structure of Quasar Continuum Sources"
Host: Madalina Furis
Title: "Magneto-optics in the Unique 25T Split-Florida Helix Magnet"
Host: Joseph Tischler
Title: "Semiconductor Moiré Superlattices: a New Material Platform for Quantum Information Science "
Host: Sean Matt
Title: "From the surface rotation of stars to their interiors, magnetism, and beyond"
Abstract: Open clusters, such as the Pleiades, Praesepe, and the Hyades, are critical benchmarks for calibrating stellar properties such as rotation and magnetic activity. As stars approach the main sequence, they contract and spin more rapidly; once they reach the main sequence, they stop contracting and their spin speed decreases over time. This spin-down is caused by angular momentum lost via stellar winds, but details of stellar wind torques and any internal angular momentum transport are still uncertain. I will discuss recent results constraining the rotation of old, low-mass stars along with young, solar-mass stars. I will show how we can use new data with a statistically robust fitting method to distinguish between models of stellar rotational evolution.
Host: Howie Baer
Title: "Building the case for future explorations at the Energy Frontier"
Host: Mukremin Kilic
Title: "Mysterious Fast Radio Bursts"
Abstract: Recently discovered Fast Radio Bursts are millisecond-long radio pulses coming half way across from the observed Universe. The peak luminosity, in radio, are billions of solar lumonicity (but just for a millisecond!). The *simplest* explanation involves a star of the order of mass of a Sun, compacted to 10 km, having quantum magnetic field of ~ 1010 Tesla, spinning at fraction of second, and having magnetopshere populated by relativistic beams of particles moving at Lorentz factor ~ 102-103. I will discuss astronomical and plasma physics challenges, and offer a few insights on the new, astrophyscailly-important plasma regime, that of an extremely magnetized relativistic plasma.
Title: "Using Photons to Understand and Change Defects in Semiconductors"
Abstract: The optical properties of semiconductors are inextricably linked to their electronic and vibrational properties. Electronic transitions from hydrogenic impurities and vibrational modes of mass defects lead to well-defined peaks in the infrared (IR) spectrum that provide information about the symmetry and chemical composition of the defects. Optical techniques such as photoluminescence (PL) provide researchers with a (mostly) nondestructive method for identifying defects. Light can also change defects, especially those that undergo large relaxation when their charge state changes. The DX center, for example, can absorb a photon and move to its shallow-donor site, leading to persistent photoconductivity (PPC) at low temperatures. In certain perovskite oxide semiconductors, substitutional hydrogen can be optically excited, causing the proton and electrons to leave. This leads to large room temperature PPC. Similar processes may cause photochromism, which is a change in sample color after exposure to light. We discovered a remarkable example of this effect in Cu-doped β-Ga2O3, an ultra-wide bandgap semiconductor.
Host: Grant Biedermann
| Date | Host | Speaker | Title |
|---|---|---|---|
02/23/2023 | Ian Sellers | Bibhudutta Rout University of North Texas | "Materials analysis and modifications using energetic ion beams" |
02/28/2023 | Xinyu Dai | Sean Matt University of Exeter | "Rotation, Magnetism, and Mass Loss of Sun-Like Stars" |
03/02/2023 | Joe Tischler | Jeremy Robinson Naval Research Laboratory | "Engineering Layered Materials" |
03/09/2023 | Xinyu Dai | Chris Hayworth | |
03/23/2023 | Nate Kaib | Nick Young University of Michigan | "Toward a More Equitable and Effective Physics Graduate Admissions Process" |
03/30/2023 | Brad Abbott | Jae Yu UT Arlington | "Exploring Physics Beyond the Standard Model with DUNE" |
04/06/2023 | Nate Kaib | Matt Clement Johns Hopkins APL | "The early secular evolution of the outer solar system and the present state of the Nice Model" |
04/13/2023 | Howie Baer | Laura Reina Florida State University | "Physics at the HEP energy frontier" |
04/20/2023 | Doerte Blume | Elizabeth Behrman Wichita State University | "A quantum generative adversarial network for mapping entanglement" |
04/27/2023 | Kieran Mullen | Greg Salamo University of Arkansas |
| Date | Host | Speaker | Title |
|---|---|---|---|
09/01/2022 | Thirumalai Venkatesan | Jeremy Levy University of Pittsburgh | "Correlated Nanoelectronics and the Second Quantum Revolution" |
09/13/2022 |
| Xinyu Dai University of Oklahoma | "Extended Extragalactic Journey with Active Galactic Nuclei, Galaxy Clusters, and Planet-Mass Objects" |
09/15/2022 |
| Kuver Sinha University of Oklahoma | "Particles or Principles? The Hunt for New Physics Across Scales" |
09/22/2022 |
| Mukremin Kilic University of Oklahoma | "Revolution in Stellar Astrophysics and the Remaining Challenges" |
09/27/2022 |
| Bruno Uchoa University of Oklahoma | "Strange metal phase and quantum thermalization in nodal materials" |
09/29/2022 | Ian Sellers | Jamie Warner University of Texas at Austin | "Probing the structure, epitaxy and bonding at the single atom level in 2D materials and small molecules using Advanced Electron Microscopy" |
10/13/2022 | Robert Lewis-Swan | Thomas Bilitewski Oklahoma State University | "Exploring Long Range Dipolar Interactions: From collective dipolar spin dynamics and layer exchange to light-mediated interactions and Pauli-Blocking" |
10/20/2022 | Karen Leighly | Paola Rodriquez Hidalgo UW Bothell | "(Extremely!) High Velocity Outflows in Quasars" |
10/27/2022 | Arne Schwettmann | Guido Pagano Rice University | "Quenches and Disorder-free Localization in Interacting Trapped-Ion Spin Chains" |
11/03/2022 | Mike Strauss | Phil Ilten University of Cincinnati |
|
11/10/2022 | Doerte Blume | Hossein Sadeghpour ITAMP/Harvard University | "Few-body and many-body games with Rydberg atoms as intermediaries" |
11/17/2022 | Howie Baer | Stefano Profumo UC Sanata Cruz | "What is the Dark Matter?" |
12/01/2022 | Xinyu Dai | Albert Chuang Former Nielsen Award Talk |
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