Events at Physics |
Events During the Week of May 3rd through May 10th, 2026
Sunday, May 3rd, 2026
- Academic Calendar
- Exams Begin
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu
Monday, May 4th, 2026
- Academic Calendar
- Exams
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu
- Preliminary Exam
- Cosmological Information Recovery from Large-Scale Structure
- Time: 10:00 am - 12:00 pm
- Place: B343 Sterling
- Speaker: Shihui Zang, Physics PhD Graduate Student
- Abstract: Large-scale structure (LSS) provides powerful and complementary constraints on cosmology, but much of its information is obscured by nonlinear gravitational evolution, galaxy bias, redshift-space distortions, and survey systematics. This prelim exam focuses on methods to recover cosmological information from LSS, with emphasis on two themes.
- Host: Moritz Munchmeyer
- Preliminary Exam
- Creating new low-switching orderings by stacking order engineering of 2D materials
- Time: 1:30 pm - 3:30 pm
- Place: B343 Sterling
- Speaker: Carter Fox, Physics PhD Graduate Student
- Abstract: By altering the stacking order of 2D van der Waals (vdW) materials, many new ferroic, strongly correlated and topological orderings emerge with exotic electrical, optical and magnetic properties. Owing to the weak vdW interlayer bonding, such highly flexible and energy-efficient stacking order engineering has transformed the design of quantum properties in 2D materials. In this talk, I present two advances enabled by stacking order engineering. First, I demonstrate the creation of a sliding multiferroic by stacking inherently non-polar layers of the 2D magnet CrI3 into a polar stacking order. Using combined optical and electrical transport characterization techniques, emergent sliding ferroelectricity is shown to interplay with interfacial ferromagnetism via interlayer spin-polarized charge transfer. This unique magnetoelectric coupling mechanism leads to non-volatile magnetic switching at zero external magnetic field, driven by voltages as low as 0.4 V across the CrI3. Second, I introduce a new domain superposition mechanism to engineer topological polar textures based on the orthogonal stacking of displacive vdW ferroelectrics. This concept is demonstrated with NbOI2 layers, where we directly observe polar vortices and related textures at overlapping domain walls via 4D-STEM. Furthermore, second harmonic generation circular dichroism reveals a robust chiroptical response, and we show that the macroscopic chiral state is reversibly controlled in four terminal devices. Together, these results highlight stacking order engineering as a versatile route to programmable multiferroic and topological states in vdW materials, opening pathways toward next generation electronic, spintronic, and photonic technologies.
- Host: Jun Xiao
Tuesday, May 5th, 2026
- Academic Calendar
- Exams
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu
Wednesday, May 6th, 2026
- Academic Calendar
- Exams
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu
- Preliminary Exam
- Neutrino astronomy and oscillations with IceCube
- Time: 10:15 am - 12:15 pm
- Place: 5310 CH
- Speaker: Samyak Jain, Physics PhD Graduate Student
- Abstract: Neutrino astronomy continues to be a rapidly evolving field. In addition to identifying a handful of neutrino sources (NGC 1068, TXS 0506+056, and the Milky Way), the IceCube Neutrino Observatory has identified a diffuse flux of astrophysical neutrinos with unclear origins. Apart from astronomy, IceCube-DeepCore has also proved capable of placing leading constraints on neutrino oscillations. These oscillations may be modified by neutrino-matter interactions beyond the Standard Model - referred to as Non-Standard Interactions (NSI) - making IceCube potentially sensitive to them. In this talk, I will motivate Active Galactic Nuclei - which are promising sites of cosmic-ray acceleration - as significant contributors to the diffuse neutrino flux, and present IceCube-DeepCore’s sensitivity to NSI.
- Host: Francis Halzen and Dan Hooper
- Thesis Defense
- The Physical Properties and Redshifts of Dusty Star-forming Galaxies: Observational Studies with ALMA and JWST
- Time: 2:00 pm - 4:00 pm
- Place: Chamberlin 5280
- Speaker: Stephen McKay
- Abstract: Dusty star-forming galaxies (DSFGs) represent an extreme phase of rapid dust-obscured galaxy assembly and are major contributors to the cosmic star-formation rate density (SFRD) at early times. For some time, a comprehensive understanding of the formation and evolution of DSFGs has been hindered by the difficulty of reliably identifying large, deep samples and determining their redshifts and physical properties. In my thesis, I present several studies using Atacama Large Millimeter/submillimeter Array (ALMA) and James Webb Space Telescope (JWST) observations to characterize the DSFG population, with a particular emphasis on the faint submillimeter population. First, I use multi-band ALMA observations of 870 μm-selected DSFGs to model their dust spectral energy distributions (SEDs) to high precision, showing that the dust properties of sources at cosmic noon are generally consistent with those seen in local galaxies and predicted by models. Using follow-up ALMA linescans along with ancillary JWST and ground-based redshifts for this sample, I construct a nearly (97%) complete spectroscopic redshift distribution for S850μm > 2 mJy DSFGs for the first time. The results illustrate the effectiveness of combining ALMA and JWST to measure DSFG redshifts, and they demonstrate that JWST is particularly effective at obtaining even high redshifts for DSFGs. However, the JWST coverage is just ~30% in the best-covered fields. I use these redshifts to test photometric redshift estimation methods and to constrain the shape of the DSFG redshift distribution. Next, I use ALMA 1.2 mm data to verify that a JWST NIR-color selection can determine accurate positions for single-dish submillimeter (JCMT/SCUBA-2) sources, including faint (S850μm < 2 mJy) DSFGs. Using panchromatic SED fits and surface brightness profile fitting, I measure the physical properties and morphologies of these NIR-selected DSFGs, finding that they sit in a lower star-formation rate (SFR) regime (SFR ~ 50-150 Msun/yr) than that probed by typical single-dish 850 μm surveys. The stellar masses and morphologies of the bright (S850μm > 2 mJy) sources are remarkably similar to those of the faint sources. Finally, I observe a low fraction of major mergers in constrast with previous studies based on rest-frame optical wavelengths, suggesting that these studies were impacted by severe dust attenuation. By helping to infer the properties of larger samples detected in future wide surveys, these studies will contribute to a precise mapping of the dust-obscured SFRD and structure assembly history of the Universe.
- Host: Stephen McKay
Thursday, May 7th, 2026
- Academic Calendar
- Exams
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu
- R. G. Herb Condensed Matter Seminar
- Title to be announced
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Shimon Kolkowitz, Berkeley
- Host: Mark Eriksson
Friday, May 8th, 2026
- Academic Calendar
- Exams End
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu
- Academic Calendar
- Commencement: Doctoral and Medical Professional
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu URL:
- Preliminary Exam
- Offset charge jumps in Si/SiGe quantum dot qubits from radiation
- Time: 10:30 am - 12:30 pm
- Place: 5310 CH
- Speaker: Brighton Coe, Physics PhD Graduate Student
- Host: Mark Eriksson
- Graduate Program Event
- Physics Graduation Celebration Event
- Time: 3:00 pm - 5:00 pm
- Place: 2241 Chamberlin
- Abstract: Come celebrate and congratulate our 2026 graduates from both the undergraduate and Ph.D. Programs! We will celebrate the Ph.D. graduates from 3:00 - 3:30, enjoy treats and ice cream from 3:30 - 4:00, and then celebrate the undergraduates from 4:00 - 5:00.
- Host: Sharon Kahn and Evan Heintz
Saturday, May 9th, 2026
- Academic Calendar
- Commencement: Bachelor’s, Master’s, Law
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu URL: