College of Engineering Seminars & Speakers

View Full Calendar

Physics Colloquium: Coloring Hofstadter's Butterfly: New Topological Invariants of Crystalline Quantum Matter

Event Type
Lecture
Sponsor
Department of Physics
Location
Loomis Lab 141 and via Zoom
Virtual
wifi event
Date
Oct 25, 2023   4:00 pm  
Speaker
Maissam Barkeshli (Maryland)
Contact
Kelly Darr
E-Mail
khdarr@illinois.edu
Phone
217-300-7821
Views
135
Originating Calendar
Physics - Colloquium

The discovery of quantized Hall conductance in the early 1980s showed how quantum phases of matter can be distinguished by topological invariants. This kicked off a decades-long quest to understand subtle distinguishing topological aspects of quantum matter. In this talk, I will describe a new set of topological invariants that arise in quantum systems with crystalline symmetry. Analogous to the quantized Hall conductance, these new invariants dictate quantized responses of the system to crystal defects. Our understanding of how to extract these invariants from quantum systems has provided the first new ways to color Hofstadter's famous fractal butterfly in over 40 years.

link for robots only