Events on Thursday, March 6th, 2025
- R. G. Herb Condensed Matter Seminar
- Quantum many-body scars in Rydberg atom simulators
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin
- Speaker: Ian Mondragon Shem, Northwestern
- Abstract: Quantum simulators have led to significant insight into the non-equilibrium behavior of quantum many-body systems. Programmable Rydberg atom simulators, in particular, have uncovered the existence of persistent oscillations of local observables due to the emergence of quantum many-body scars. The conventional understanding of these scar states purports that they form a small subset of non-ergodic eigenstates embedded in a thermal spectrum. In this talk, we will show that the PXP model, which closely describes strongly interacting Rydberg atoms, can exhibit many more scarred states than had been previously identified. We will present evidence that the magnetization and temporal correlators of the system exhibit oscillations for almost any initial product state with a frequency close to that of the conventional set of scars. We will argue that these oscillations arise due to multiple sets of scars that satisfy an approximate su(2) algebra. We will further explore the impact that this structure has on the system's dynamics in the presence of disorder. Finally, we will discuss a strategy to detect the presence of these new scarred states using quantum typically.
- Host: Maxim Vavilov
- Astronomy Colloquium
- The Milky Way as a Prototypical Disk Galaxy: Galactic Archeology and Chemical Evolution in Context
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Boquan Erwin Chen, Ohio State University
- Abstract: The chemical evolution of the Milky Way has long been regarded as uniquely complex, epitomized by its distinct dual [α/Fe] sequences. This perceived intricacy has driven interpretations reliant on multi-phase formation models, such as the two-infall framework. Yet, breakthroughs in Galactic archeology—powered by Gaia astrometry and large-scale spectroscopic surveys—are challenging this narrative, revealing that the Milky Way’s chemical evolution may align closely with processes observed in typical disk galaxies. In this talk, I will present a unified, physically motivated model of chemical evolution that reframes the Milky Way not as an outlier but as a galactic archetype. We demonstrate that key observables—including the radial metallicity gradient, stellar metallicity distribution, and age-abundance trends—can be simultaneously reproduced under a coherent framework consistent with generic disk galaxy formation. By reconciling these features without invoking exceptional mechanisms, our results suggest that the Milky Way’s apparent complexity stems from its detailed observational record rather than atypical evolutionary pathways. Furthermore, the archetypal nature of the Milky Way may extend to its very origins, implying that its early assembly followed pathways common to disk galaxies. Nevertheless, stellar-level observations of the M31 Andromeda galaxy and Large Magellanic Cloud (LMC) highlight the diversity of galactic chemical evolution. This renewed perspective positions our Galaxy as a critical benchmark for deciphering the universal processes shaping disk galaxies across cosmic time, offering insights that bridge local precision to extragalactic contexts.
- Host: Melinda Soares-Furtado
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Seeing with Structure: Physics and The Art of Model-Building
- Time: 4:00 pm - 5:00 pm
- Place: 5280 CH &
- Speaker: Dr. Garrett Merz, University of Wisconsin - Madison
- Abstract: Physics datasets are highly structured, and studying how and when this structure is (or is not) learnable by neural network models offers an exciting new way to pose questions about our data. In this talk, I will explore applications of this thinking to problems in both experimental and theoretical high-energy physics: to the discovery of new patterns in the mathematical structure of theoretical physics data, to large-scale "Foundation Modelling" questions that span diverse experimental settings ranging from collider physics to cosmology, and to pose future questions that might allow us to bridge the gap between experimental and theoretical domains. By studying how and when models represent symmetries and patterns, I explore ways in which physicists can use models themselves as structure probes, which may enable radically new ways of formulating questions about the Universe.
- Host: Sridhara Dasu