Events on Thursday, October 2nd, 2025
- R. G. Herb Condensed Matter Seminar
- Cavity QED with molecular defects coupled to a photonic crystal cavity
- Time: 10:00 am - 11:00 am
- Place: 5310 Chamberlin
- Speaker: Jonathan Hood, Purdue
- Abstract: We implement permanent spectral tuning to bring lifetime-limited emitters into collective resonance within an integrated photonic cavity. This addresses a fundamental challenge in solid-state cavity QED: combining multiple coherent quantum emitters with scalable nanophotonics. Our hybrid approach decouples emitter synthesis from nanophotonic fabrication using straightforward techniques that make cavity QED broadly accessible. Building on our previous demonstration of superradiance and subradiance in pairs of molecules [1], we now couple several coherent emitters to a single cavity mode through high doping densities. Optically-induced frequency shifting provides long-lived spectral control, allowing us to tune multiple molecules into resonance and demonstrate controlled formation of collective quantum states [2]. This establishes a scalable platform for many-body cavity QED and opens pathways toward chemically-designed quantum systems where optical properties are engineered through synthetic chemistry. We will also report on progress in our ultracold Li-Cs experiment, including cooling with the narrow 5D transition [3]. [1] C. Lange, E. Daggett, V. Walther, L. Huang, and J.D. Hood, Nature Physics (2024) [2] C. Lange et al., arXiv:2406.01917 (2025) [3] Blodgett et al., arXiv :2505.10540 (2025)
- Host: Mark Saffman
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Cosmic ray processes across the Universe: multi-messenger insights form Galaxies to the Cosmic Web
- Time: 2:30 pm - 3:30 pm
- Place: Chamberlin Hall, Room 5280
- Speaker: Ellis Owen, RIKEN, Japan
- Abstract: Cosmic rays interact with astrophysical systems across a vast range of scales, from turbulent galactic environments to the large-scale structure of the Universe. Closely linked to violent, high-energy processes, they act as a dynamic feedback agent, regulating the physical conditions and long-term evolution of galactic and circum-galactic ecosystems. Depending on their energy, cosmic rays can also escape from their host galaxies, propagate through the cosmic web, and produce multi-wavelength and multi-messenger signatures that encode information about their interactions, environments, and transport physics. In this talk, I will highlight key observational tracers, including those from multi-messenger probes, that can be used to map the physical effects of cosmic rays across astrophysical environments and extend studies of galaxies beyond traditional astronomical techniques. I will also examine the role of cosmic rays in shaping baryonic flows around galaxies, and discuss their fate as they traverse the magnetized large-scale structures of the Universe, including the highest-energy particles that may never reach us on Earth.
- Host: Ellen Zweibel