Floquet Chern insulators of light

Journal Article · 13 September 2019 · Nature Communications

DOI: https://doi.org/10.1038/s41467-019-12231-4 · OSTI ID:1624194

He, Li ^[1]; Addison, Zachariah ^[1]; Jin, Jicheng ^[1]; Mele, Eugene J. ^[1]; Johnson, Steven G. ^[2]; Zhen, Bo ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States). Dept. of Physics and Astronomy
2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Mathematics

Achieving topologically-protected robust transport in optical systems has recently been of great interest. Most studied topological photonic structures can be understood by solving the eigenvalue problem of Maxwell’s equations for static linear systems. Here, we extend topological phases into dynamically driven systems and achieve a Floquet Chern insulator of light in nonlinear photonic crystals (PhCs). Specifically, we start by presenting the Floquet eigenvalue problem in driven two-dimensional PhCs. We then define topological invariant associated with Floquet bands, and show that topological band gaps with non-zero Chern number can be opened by breaking time-reversal symmetry through the driving field. Finally, we numerically demonstrate the existence of chiral edge states at the interfaces between a Floquet Chern insulator and normal insulators, where the transport is non-reciprocal and uni-directional. Our work paves the way to further exploring topological phases in driven optical systems and their optoelectronic applications.

• Research Organization: Pennsylvania State Univ., University Park, PA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: FG02-00ER41132
• OSTI ID: 1624194
• Journal Information: Nature Communications, Vol. 10, Issue 1; ISSN 2041-1723
• Publisher: Nature Publishing GroupCopyright Statement
• Country of Publication: United States
• Language: English