Band structures of strained kagome lattices

Abstract

Abstract Materials with kagome lattice have attracted significant research attention due to their nontrivial features in energy bands. In this work, we theoretically investigate the evolution of electronic band structures of kagome lattice in response to uniaxial strain using both a tight-binding model and an antidot model based on a periodic muffin-tin potential. It is found that the Dirac points move with applied strain. Furthermore, the flat band of unstrained kagome lattice is found to develop into a highly anisotropic shape under a stretching strain along y direction, forming a partially flat band with a region dispersionless along ky direction while dispersive along kx direction. Our results shed light on the possibility of engineering the electronic band structures of kagome materials by mechanical strain.