Loading Events

« All Events

  • This event has passed.

Optical axion electrodynamics

November 2, 2022 @ 9:00 am - 10:00 am

CMSA Topological Seminar 11.2.22

Topological Quantum Matter Seminar

Speaker: Junyeong Ahn (Harvard)

Title: Optical axion electrodynamics

Abstract: Electromagnetic fields in a magneto-electric medium behave in close analogy to photons coupled to the hypothetical elementary particle, the axion. This emergent axion electrodynamics is expected to provide novel ways to detect and control material properties with electromagnetic fields. Despite having been studied intensively for over a decade, its theoretical understanding remains mostly confined to the static limit. Formulating axion electrodynamics at general optical frequencies requires resolving the difficulty of calculating optical magneto-electric coupling in periodic systems and demands a proper generalization of the axion field. In this talk, I will introduce a theory of optical axion electrodynamics that allows for a simple quantitative analysis. Then, I will move on to discuss the issue of the Kerr effect in axion antiferromagnets, refuting the conventional wisdom that the Kerr effect is a measure of the net magnetic moment. Finally, I will apply our theory to a topological antiferromagnet MnBi2Te4.

[1] Theory of Optical Axion Electrodynamics, J. Ahn, S.Y. Xu, A.Vishwanath, arXiv:2205.06843


November 2, 2022
9:00 am - 10:00 am
Event Category:


Jie Wang


CMSA Room G10
CMSA, 20 Garden Street
Cambridge, MA 02138 United States
+ Google Map