Events at Physics |
Events on Wednesday, April 29th, 2026
- Atomic Physics Seminar
- Quantum nodes with group IV color centers in diamond: from optical antennas to axial-free spins
- Time: 10:00 am - 11:00 am
- Place: Chamberlin 5310
- Speaker: Zixi Li, University of Chicago
- Abstract: Atom-like defects in solids are promising building blocks for quantum technologies, combining the controllability of isolated quantum systems with the versatility of a solid-state platform. Among these, group-IV color centers in diamond are especially attractive because their inversion symmetry supports excellent optical coherence, while their electronic and spin properties remain highly tunable through the local solid-state environment. In this talk, I will discuss two directions in which these defects can be harnessed as new kinds of quantum sensors. First, I will show that a resonantly driven germanium-vacancy center can function as an atomic optical antenna, generating a strongly enhanced local optical field that enables the sensing and control of nearby charge defects. Second, I will describe ongoing work showing that large strain can reshape the spin-orbital structure of group-IV centers, partially release the electron spin from its usual locking to the defect axis and allow its quantization axis to be modified by an external magnetic field, which provides a route to accessing and detecting a broader set of surrounding nuclear spins. Together, these results illustrate how group-IV color centers can be developed into novel quantum sensors in diamond from both optical and spin perspectives.
- Host: Mark Saffman
- Department Meeting
- Time: 12:15 pm - 1:15 pm
- Place: B343 Sterling
- Speaker: Kevin Black, UW - Madison, Department of Physics
- Department Meeting
- Host: Kevin Black
- Astronomy Colloquium
- Whitford Public Talk: The Mysteries of Cosmic Dust
- Time: 7:00 pm - 8:30 pm
- Place: 1310 Sterling Hall
- Speaker: Bruce Draine, Princeton University
- Abstract: The first galaxies form stars out of initially pristine gas. After a
few million years the gas is enriched with heavy elements formed by
the first generation of stars. Dust starts to appear in small
amounts, and H2 formation by catalysis on dust grains begins.
JWST Spectroscopy of I Zw 18, a very metal-poor star-forming galaxy in
the nearby universe, provides an opportunity to study these
beginnings. The composition of the first dust is found to be very
different from dust in a mature galaxy such as the Milky Way. The
molecular hydrogen emission spectrum allows the ortho/para ratio to be
determined, with the ortho/para ratio found to exceed 3 in some regions.
Implications will be discussed.