The kagome lattice is a fundamental model structure in condensed matter physics and materials science featuring symmetry-protected flat bands, saddle points, and Dirac points. This structure has emerged as an ideal platform for exploring various quantum physics. By combining effective model analysis and first-principles calculations, we propose that the synergy among inversion symmetry breaking, flat bands, and saddle point-related van Hove singularities within the kagome lattice holds significant potential for generating strong second-order nonlinear optical response. This property provides an inspiring insight into the practical application of the kagome-like materials, which is helpful for a comprehensive understanding of kagome lattice-related physics. Moreover, this work offers an alternative approach for designing materials with strong a second-order nonlinear optical response.
@article{arxiv.2505.08289,
title = {Nonlinear optical response in kagome lattice with inversion symmetry breaking},
author = {Xiangyang Liu and Junwen Lai and Jie Zhan and Tianye Yu and Peitao Liu and Seiji Yunoki and Xing-Qiu Chen and Yan Sun},
journal= {arXiv preprint arXiv:2505.08289},
year = {2025}
}