Photonic Weyl point in a two-dimensional resonator lattice with a synthetic frequency dimension

• Published in: Nature communications Vol. 7; no. 1; p. 13731
• Main Authors: Lin, Qian, Xiao, Meng, Yuan, Luqi, Fan, Shanhui
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 15.12.2016; Nature Publishing Group; Nature Portfolio
• Subjects: 639/624/399/1015; 639/624/400; Humanities and Social Sciences; multidisciplinary; Physics; Science; Science (multidisciplinary); United States > US; California
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms13731

Weyl points, as a signature of 3D topological states, have been extensively studied in condensed matter systems. Recently, the physics of Weyl points has also been explored in electromagnetic structures such as photonic crystals and metamaterials. These structures typically have complex three-dimensional geometries, which limits the potential for exploring Weyl point physics in on-chip integrated systems. Here we show that Weyl point physics emerges in a system of two-dimensional arrays of resonators undergoing dynamic modulation of refractive index. In addition, the phase of modulation can be controlled to explore Weyl points under different symmetries. Furthermore, unlike static structures, in this system the non-trivial topology of the Weyl point manifests in terms of surface state arcs in the synthetic space that exhibit one-way frequency conversion. Our system therefore provides a versatile platform to explore and exploit Weyl point physics on chip. Weyl points, point degeneracies surrounded by linear dispersions, are the 3-dimensional analogue of the Dirac points known from 2D materials. Here, Lin et al . propose a scheme for realizing on-chip electromagnetic Weyl points by utilizing the concept of synthetic dimensions.