Events on Thursday, October 3rd, 2024
- R. G. Herb Condensed Matter Seminar
- Experiments with Strontium Rydberg States: Spatial Correlations and Synthetic Dimensions
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin
- Speaker: Yi Lu, Rice
- Abstract: Rydberg states provide wonderful platforms for studying dynamics and correlations in quantum systems with ultracold atoms. Our experiments with strontium ultralong-range Rydberg molecules (ULRRM) have demonstrated that the photo-association rate of ULRRMs can be used to probe non-local spatial correlations in a quantum gas, such as bunching and antibunching of bosonic and fermionic isotopes of strontium gases [1]. More recently, we also resolved rotational states of ULRRMs and used them to observe the s-wave suppression of the 86Sr-86Sr pair (with scattering length as=823a0). [2] I will also share in this talk our efforts and results of constructing synthetic dimensions with Rydberg atomic states. We realized the Su-Schrieffer-Heeger (SSH) model used six 3S1 Rydberg levels with microwave frequencies resonantly connecting adjacent pairs. Edge-to-edge long-range tunneling and bulk-population oscillations, characteristic behaviors of the topological phase, were observed in the measured population evolution [3]. The strong/weak tunneling ratio is also scanned to probe the topological-trivial phase transition in the SSH model through measurements of the band structure and the winding number [4]. [1] Whalen, et al., Phys. Rev. A 100, 011402(R) (2019) [2] Lu, et al., Phys. Rev. A 106, 022809 (2022) [3] Lu, et al., Phys. Rev. A 109, 032801 (2024) [4] Lu, et al., Phys. Rev. A 110, 023318 (2024)
- Host: Mark Saffman
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Mapping cosmic star formation with the CO Mapping Array Project
- Time: 2:30 pm - 3:30 pm
- Place: Chamberlin Hall Room 5280
- Speaker: Patrick Breysse, Southern Methodist University
- Abstract: The process of star formation is key to our understanding of galaxies, as well as the use of galaxies to probe fundamental physics. Measuring star formation at high-redshift, however, is often difficult and expensive. In this talk, I will discuss the results of the second observing season of the CO Mapping Array Project (COMAP), which uses the new observational technique of line intensity mapping to explore cosmic star formation from a new angle. COMAP has reported the deepest ever intensity mapping observation of the dense-gas tracing CO(1-0) emission line near cosmic noon. I will provide an overview of the COMAP results, and discuss how results from it and other early intensity mapping measurements may hint at excess star formation beyond which is predicted by current galaxy models. I will close by discussing exciting future extensions to COMAP happening in the next few years.
- Host: Peter Timbie
- Astronomy Colloquium
- The Massive Ancient Galaxies At z>3 NEar-infrared Survey -- Hunting Monster Galaxies in the Early Universe
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Ian McConachie, UW-Madison
- Abstract: One of the most important mysteries in the field of galaxy evolution is when, where, and how the most massive galaxies formed and assembled their mass in the early Universe. Early ultra-massive galaxies (UMGs) place strong constraints on models for galaxy formation and evolution. Large near-infrared photometric surveys have revealed numerous UMG candidates at increasingly high redshifts through the past decade, but spectroscopic followup is necessary to confirm their nature. In this talk I will first provide an overview of the MAGAZ3NE spectroscopic survey, which targeted UMG candidates to characterize their stellar populations and their environments. I will then discuss the three protoclusters we discovered around UMGs and the insights they give to UMG evolution. Finally, I will present results from MAGAZ3NE’s spectroscopic campaign searching for the reddest, most massive UMG candidates and the subsequent implications for the extremely high-mass end of the stellar mass function.
- Host: Melinda Soares-Furtado