title: Multiple flat photonic bands with finite Chern numbers.
abstract: We show both analytically and numerically that there is an infinite number of flat bands with different Chern numbers in a two-dimensional magnetic photonic crystal at nearly the same frequency determined by the condition that the effective magnetic permeability μ_{eff}≈-1. This opens the door to explore the physics involving higher order topological invariants in this system. The frequency of these states can be flexibly tuned by an external magnetic field.
authors.affiliation: Department of Physics and Astronomy and Bartol Research Institute, University of Delaware, Newark, Delaware 19716, USA.
authors.forename: S T
authors.initials: ST
authors.lastname: Chui
authors.forename: Shiyang
authors.initials: S
authors.lastname: Liu
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Lin