Band engineering method to create Dirac cones of accidental degeneracy in general photonic crystals without symmetry
Type
ArticleDate
2021-05-25Online Publication Date
2021-05-25Print Publication Date
2021-06-07Submitted Date
2021-04-09Permanent link to this record
http://hdl.handle.net/10754/669286
Metadata
Show full item recordAbstract
Symmetry usually plays a key role in the formation of the Dirac cone in the band structure of triangular or hexagonal systems. In this work, we demonstrate a systematic method to create Dirac cones of accidental degeneracy in general photonic crystals without symmetry. With this method, a band gap can be closed gradually through a series of modification to the unit structure based on the eigenfields of the band edges, and consequently a Dirac point is formed with Dirac conical dispersions in its vicinity. The validity of this approach is demonstrated by three examples. We further show that the Dirac cones of accidental degeneracy have the same properties as the symmetry-induced Dirac cones, such as finite group velocity and pseudo-diffusive transmission. Our finding opens a route for the engineering of accidental degeneracy in general photonic crystals beyond the scope of high-symmetry ones.Citation
Chu, H., Zhang, Y., Luo, J., Xu, C., Xiong, X., Peng, R., … Lai, Y. (2021). Band engineering method to create Dirac cones of accidental degeneracy in general photonic crystals without symmetry. Optics Express, 29(12), 18070. doi:10.1364/oe.427389Publisher
The Optical SocietyJournal
Optics ExpressAdditional Links
https://www.osapublishing.org/abstract.cfm?URI=oe-29-12-18070https://doi.org/10.1364/oe.427389
ae974a485f413a2113503eed53cd6c53
10.1364/oe.427389
Scopus Count
Except where otherwise noted, this item's license is described as Archived with thanks to The Optical Society under a Creative Commons license, details at: https://creativecommons.org/licenses/by/4.0/