Realization of a Two-Dimensional Checkerboard Lattice in Monolayer Cu<sub>2</sub>N
Xuegao Hu, Run‐Wu Zhang, Da‐Shuai Ma, Zhihao Cai, Daiyu Geng, Zhenyu Sun, Qiaoxiao Zhao, Jisong Gao, Peng Cheng, Lan Chen, Kehui Wu, Yugui Yao, Baojie Feng
Abstract
Two-dimensional checkerboard lattice, the simplest line-graph lattice, has been intensively studied as a toy model, while material design and synthesis remain elusive. Here, we report theoretical prediction and experimental realization of the checkerboard lattice in monolayer Cu 2 N. Experimentally, monolayer Cu 2 N can be realized in the well-known N/Cu(100) and N/Cu(111) systems that were previously mistakenly believed to be insulators. Combined angle-resolved photoemission spectroscopy measurements, first-principles calculations, and tight-binding analysis show that both systems host checkerboard-derived hole pockets near the Fermi level. In addition, monolayer Cu 2 N has outstanding stability in air and organic solvents, which is crucial for further device applications.