Events on Thursday, March 26th, 2026
- R. G. Herb Condensed Matter Seminar
- Quantum Information on Quantum Matter
- Time: 9:00 am - 6:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Dafei Jin, University of Notre Dame
- Abstract: Abstract: Noble-gas atoms, such as helium and neon, form condensed quantum liquids and solids at low temperatures. They are among the purest matters in nature, free of chemical contamination or usual two-level fluctuators. and can serve as ideal hosts for quantum information carriers. In this talk, I will present our development of noise-resilient, coherently interacting electron qubits on the surface of solid neon in a superconducting quantum circuit. I will also present our ongoing effort to deterministically trap atoms and ions in quantum solids for broader quantum information applications. Bio: Dafei Jin is an Associate Professor of Physics and Electrical Engineering at the University of Notre Dame. His research lies at the intersection of condensed matter physics and quantum information science. In recent years, he pioneered the development of quantum information platforms based on electrons trapped on quantum-solid surfaces. He is a recipient of the 2021 Julian Schwinger Foundation Award for Physical Research and the 2024 DOE Early Career Award.
- Host: Ilya Esterlis
- Astronomy Colloquium
- Toward Real Rocky Planet Interiors with Ideal Multicomponent Mixing
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Dr. David Rice, UW-Madison
- Abstract: As observational precision improves, a leading uncertainty in exoplanet interior inference is no longer the data but our models of realistic, multicomponent interiors. I present a mixing framework focused on planets less than 10 Earth-masses that treats differentiated layers as chemically consistent mixtures rather than endmembers. We implement this framework in the open-source planet interior code Magrathea. We solve the mineralogy of rocky mantles in closed form from four elemental ratios, Ca/Mg, Si/Mg, Al/Mg, Fe/Mg, using stoichiometric relationships to keep the mantle in chemical equilibrium across upper and lower regions. The resulting phase proportions of Fe–Mg silicates and accessory Ca- and Al-bearing minerals are broadly consistent with mineralogy from Perple_X Gibbs free-energy minimization but are obtained with a much faster and auditable scheme. We then use ideal mixing to translate these assemblages into density and an adiabatic temperature gradient. We extend the same machinery to tests of light elements in metallic cores, rock–water mixing, and mixed atmosphere species. In each case, we highlight where composition inferences are most sensitive to mixing assumptions. These developments build on the modular equation-of-state and phase-diagram infrastructure of Magrathea v2, enabling reproducible model intercomparisons where differences can be traced to specific materials, phases, and mixing choices rather than hidden defaults.
- Host: Juliette Becker