## The Anthony J Leggett Institute for Condensed Matter Physics Seminar: "Topological responses and de Haas-van Alphen effect of a Fermi surface from coajoint-orbit bosonization"

- Event Type
- Seminar/Symposium
- Sponsor
- Physics Department
- Location
- ESB 190
- Date
- Nov 11, 2024 12:00 pm
- Speaker
- Yuxuan Wang, University of Florida
- Contact
- Ljubica Milutinovic
- ljubicam@illinois.edu
- Phone
- 217-300-6393
- Views
- 14
- Originating Calendar
- Physics - The Anthony J Leggett Institute for Condensed Matter Theory Seminar
We present a bosonized effective field theory for a 2d Fermi surface in a weak magnetic field using the coadjoint orbit approach, which was recently developed as a nonlinear bosonization method in phase space for Fermi liquids and non-Fermi liquids. By using techniques in noncommutative field theory, the resulting theory describes $N_{\Phi}$ flavors of free chiral bosons propagating in momentum space, consistent with a Chern-Simons response theory in phase space and its associated LU(1) ’t Hooft anomaly. In addition, the action contains a linear term in the bosonic field, which upon mode expansion becomes a topological $\theta$-term. By properly quantizing this theory, we obtain thermal and magnetic responses of a Fermi surface, including linear-in-$T$ specific heat, Landau diamagnetism, and the de Haas-van Alphen effect. In particular, the de Haas-van Alphen effect, an essential singularity in response to an external field $B$, is shown to be a direct consequence of the topological $\theta$-term.