Events at Physics |
Events on Tuesday, September 22nd, 2026
- Preliminary Exam
- Random-Alloy Disorder Analysis in Si/SiGe Systems
- Time: 2:00 pm - 4:00 pm
- Place: 5310 Chamberlin
- Speaker: Emma Brann, Physics PhD Graduate Student
- Abstract: Si/SiGe heterostructures look promising as a scalable platform for quantum computing, but the degeneracy between the low-lying states in the silicon conduction band currently limits device fidelity. Introducing a small concentration of germanium to the quantum well offers a solution to this "valley splitting problem" by introducing random-alloy disorder. In this work, we examine the influence of this disorder in experimental results, comparing data trends and correlations against simulated and analytical results. We also present a numerical framework designed to reproduce disorder-induced errors using simulated charge stability diagrams.
- Host: Mark Friesen
- WiCOR Lecture - Fall 2026
- Planet 9 From Outer Space
- Time: 7:00 pm - 8:00 pm
- Place: Forum at the Discovery Building
- Speaker: Konstantin Batygin, Professor, Division of Geological & Planetary Sciences, Caltech
- Abstract: Over the past two decades, surveys of the outer Solar System have revealed a remarkably complex Kuiper Belt. Most of this structure can be understood through the gravitational influence of the known planets, particularly Neptune. Yet the most distant trans-Neptunian objects present several enduring puzzles: some follow elongated orbits that cluster together and remain detached from Neptune, while others occupy highly inclined or even retrograde trajectories that are difficult to produce within conventional models of Solar System evolution.
Taken together, these peculiar orbital patterns may point to the presence of an additional, as-yet-undetected planet. This object — Planet Nine — is predicted to have roughly five times the mass of Earth and to travel around the Sun on a distant, eccentric orbit with a period of approximately ten thousand years. In this talk, I will review the observational evidence that motivated the Planet Nine hypothesis, explain the dynamical mechanisms by which such a planet could sculpt the distant Solar System, and discuss current observational efforts and the prospects for its detection. - Host: WiCOR, Juliette Becker