Yang Jing, Li Yuanzhen, Yang Yumeng, Xie Xinrong, Zhang Zijian, Yuan Jiale, Cai Han, Wang Da-Wei, Gao Fei
Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, and State Key Laboratory for Extreme Photonics and Instrumentation, Zhejiang University, Hangzhou, China.
ZJU-Hangzhou Global Science and Technology Innovation Center, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China.
Nat Commun. 2024 Feb 19;15(1):1484. doi: 10.1038/s41467-024-45580-w.
Flatbands play an important role in correlated quantum matter and have promising applications in photonic lattices. Synthetic magnetic fields and destructive interference in lattices are traditionally used to obtain flatbands. However, such methods can only obtain a few flatbands with most bands remaining dispersive. Here we realize all-band-flat photonic lattices of an arbitrary size by precisely controlling the coupling strengths between lattice sites to mimic those in Fock-state lattices. This allows us to go beyond the perturbative regime of strain engineering and group all eigenmodes in flatbands, which simultaneously achieves high band flatness and large usable bandwidth. We map out the distribution of each flatband in the lattices and selectively excite the eigenmodes with different chiralities. Our method paves a way in controlling band structure and topology of photonic lattices.
平带在关联量子物质中起着重要作用，并且在光子晶格中具有广阔的应用前景。传统上，利用合成磁场和晶格中的相消干涉来获得平带。然而，这些方法只能获得少数平带，大多数能带仍然是色散的。在这里，我们通过精确控制晶格位点之间的耦合强度，以模拟福克态晶格中的耦合强度，实现了任意尺寸的全带平光子晶格。这使我们能够超越应变工程的微扰 regime，并将所有本征模归为平带，同时实现高的能带平坦度和大的可用带宽。我们绘制了晶格中每个平带的分布，并选择性地激发具有不同手性的本征模。我们的方法为控制光子晶格的能带结构和拓扑结构铺平了道路。
