Electro-elastic fields due to a point charge in a flexoelectric medium

Flexoelectricity provides a two-way connection between strain gradients and polarization that is pronounced at the nanoscale for isotropic materials which cannot link electromechanically via piezoelectricity. In this paper, the general equations for an isotropic, flexoelectric material were formulated, with contributions from strain gradients included. The electromechanical fields associated with a point charge in an infinite medium were derived, and results for GaAs were obtained. Our formulation yields two electromechanical length-scales, instead of one obtained from previous theories, and enables us to capture local fields accurately. Results from this paper provide insight into the electro-mechanical behavior of materials with charged defects.