2014/11/30 by Yiqi Zhang, Zhenkun Wu, Milivoj R. Belić +4 · 78 citations
Physics and Astronomy · #Coupling (piping) #Dirac fermion #Floquet theory #Lattice (music) #Photonic crystal #Photonics #Photorefractive and Nonlinear Optics #Quantum Mechanics and Non-Hermitian Physics #Scattering #Topological Materials and Phenomena #Topological insulator #Zigzag #physics.optics
paper · pdf · doi:10.1002/lpor.201400428
published in Laser & Photonics Review 9(3), 331-338 (Wiley) · 14 pages, 6 figures
openalex publication_date 2015/04/07 · arxiv created 2015/10/28 · arxiv updated 2015/10/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The feasibility of realizing a photonic Floquet topological insulator (PFTI) in an atomic ensemble is demonstrated. The interference of three coupling fields will split energy levels periodically, to form a periodic refractive index structure with honeycomb profile that can be adjusted by different frequency detunings and intensities of the coupling fields. This in turn will affect the appearance of Dirac cones in momentum space. When the honeycomb lattice sites are helically ordered along the propagation direction, gaps open at Dirac points, and one obtains a PFTI in an atomic vapor. An obliquely incident beam will be able to move along the zigzag edge of the lattice without scattering energy into the PFTI, due to the confinement of edge states. The appearance of Dirac cones and the formation of a photonic Floquet topological insulator can be shut down by the third-order nonlinear susceptibility and opened up by the fifth-order one.