General Method to Construct Flat Bands in Two-Dimensional Lattices
H. T. Li, Tongzhou Ji, R. G. Yan, Wenlin Fan, Z. X. Zhang, Liang Sun, B. F. Miao, Gang Chen, Xiangang Wan, Haifeng Ding
Abstract
Searching for new materials hosting flat bands is pivotal for exploring strongly correlated effects and designing sensitive quantum devices, but remains challenging. We present a general method for realizing flat bands based on mathematical optimization and symmetry analysis. The method enables the discovery of ∼1000 types of two-dimensional lattices that can host flat bands, in sharp contrast with ∼10 flat-band lattices predicted previously besides the well-known ones. We further verify the method using first-principles calculations. Our approach provides new insights for the design of flat-band lattices, particularly when aiming to create experimentally feasible configurations.