Physics Colloquium of 8 March 2022

"From the Kondo Problem to Wilson Lines —- Defects in Many-Body Systems"
Zohar Komargodski, Simons Center for Geometry and Physics, Stony Brook Univ.

We review the role of defects in many-body systems and in Quantum Field Theory. The Kondo defect has led to the Renormalization-Group and Wilson line defects have been paramount in the classification of low-energy phases of gauge theories. We review some recent progress on the topic of defects in magnets and in gauge theories. We define a notion of zero-temperature impurity entropy and argue that it captures the number of degrees of freedom on the impurity. We demonstrate this idea for magnetic impurities, pinning field impurities, and Wilson lines, making several experimental predictions on the way.

Search videos

 

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation for the State University of New York on behalf of Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit applied science and technology organization.

BSA logos