Bleustein-Gulyaev waves in topological insulators with piezoeléctric properties

A topological insulator with piezoelectric properties is considered and an action is proposed in order to find the equations of motion and the constitutive relations of the generalized coordinates of electrodynamic and elastic origin, paying special attention to the changes induced by the topological properties and the piezoelectric coupling on the magnetoelectric and electroelastic effects. The results are used to demonstrate that the electromechanical factor of the Bleustein-Gulyaev waves on the surface of a topological piezoelectric crystal of class C_6v in contact with vacuum undergoes a second order correction in the fine structure constant, associated with the topological properties.