Nonlinear optical response in kagome lattice with inversion symmetry breaking

TL;DR

This paper investigates how breaking inversion symmetry in kagome lattices enhances their nonlinear optical response, combining theoretical models and first-principles calculations to suggest new material design strategies.

Contribution

It demonstrates that inversion symmetry breaking combined with flat bands and van Hove singularities in kagome lattices can significantly boost second-order nonlinear optical responses.

Findings

Inversion symmetry breaking enhances nonlinear optical effects.

Flat bands and saddle points contribute to strong responses.

Provides a new approach for designing nonlinear optical materials.

Abstract

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.