Abstract

Emergent structural and electronic orders in crystals give rise to anisotropic response properties that can be used as probes of these order parameters and resultant phases. Both linear and nonlinear response properties, including elastic, optical, and transport properties, can be represented using tensors, and first principles calculations are often use to calculate many tensorial properties. In this talk, after reviewing well established group theory approaches, we will show that the response tensors of arbitrary rank can be decomposed into different representations of the point group, which in turn correspond to different order parameters. By considering the ferroaxial (or ferrorotational) phase transitions as an example, we will show that the emergence of an axial vector in a cubic solid corresponds to new components of piezoconductivity and elastoresistivity tensors to become nonzero. We will support this predictions with density functional theory results on a novel ferroaxial material CaSnF6 discovered through a symmetry-guided materials database search, and conclude by discussing how symmetry-informed approached can make electronic structure calculations.

Reference: https://arxiv.org/abs/2405.02149