Laser & Optoelectronics Progress, Volume. 58, Issue 7, 0713001(2021)
Optimal Design of Topological Boundary States with Large Bandwidth and Intense Localization
To solve the problem of weak local boundary states and narrow bandwidth in the model that produces the photon quantum Hall effect, in this paper, a triangular compound lattice photonic crystal is constructed, and the energy band degeneracy of the reduced Brillouin zone is used to obtain the odd parity p orbital and the even-parity d orbital. First, the position of the two orbitals is reversed by the unit cell scaling to change the topological phase. Then, the main factors affecting the band gap of topologically trivial structure and non-trivial structure are analyzed. Finally, the radii and scaling distances of dielectric cylinders of the two structures are optimized. The optimal parameters for achieving the maximum common band gap of the two structures are obtained. The maximum achievable relative bandwidth is 24.59%. Based on the optimal structure parameters, the boundary structure is constructed, and the boundary states dispersion curve is calculated. The results showed that the boundary states have strong spin direction locking and boundary electromagnetic field local effects when the effective bandwidth is 0.0435.
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Erpan Fan, Yuntuan Fang. Optimal Design of Topological Boundary States with Large Bandwidth and Intense Localization[J]. Laser & Optoelectronics Progress, 2021, 58(7): 0713001
Category: Integrated Optics
Received: Jul. 6, 2020
Accepted: Aug. 25, 2020
Published Online: Apr. 25, 2021
The Author Email: Fang Yuntuan (fang_yt1965@sina.com)