Controllable flatbands via non-Hermiticity

被引:5
作者
Lin, Shirong [1 ,2 ,3 ]
Liang, Yao [1 ]
Zhang, Jingcheng [1 ]
Chen, Mu Ku [1 ,4 ,5 ]
Tsai, Din Ping [1 ,4 ,5 ]
机构
[1] City Univ Hong Kong, Dept Elect Engn, Kowloon, Hong Kong 999077, Peoples R China
[2] Great Bay Univ, Sch Phys Sci, Dongguan 523000, Peoples R China
[3] Great Bay Inst Adv Study, Dongguan 523000, Peoples R China
[4] City Univ Hong Kong, State Key Lab Terahertz & Millimeter Waves, Kowloon, Hong Kong 999077, Peoples R China
[5] City Univ Hong Kong, Ctr Biosyst Neurosci & Nanotechnol, Kowloon, Hong Kong 999077, Peoples R China
基金
中国国家自然科学基金;
关键词
WAVE-GUIDE; LATTICES; CAGES;
D O I
10.1063/5.0174456
中图分类号
O59 [应用物理学];
学科分类号
摘要
We propose a flexible way to design and control flatbands in photonic systems with balanced gain and loss. We investigate a lattice model constructed from two parity-time (PT)-symmetric dimer systems, which give rise to two flatbands. By tuning the non-Hermiticity in this composite lattice, the flatbands can be manipulated into the regime of the dispersive bands and remain completely flat, which is protected by the PT symmetry. When reaching the exceptional point (EP), where two flatbands merge into one flatband, and surpassing the EP, one of the flatbands transforms into a partial flatband, while the imaginary parts of the band structure also appear in the form of multiple flatbands. We also discover that dimensionality plays an important role in controlling flatbands in a non-Hermitian manner. Our results could be potentially important for manipulating the dynamics and localization of light in non-Hermitian open systems.
引用
收藏
页数:7
相关论文
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