Energy allocation in piezoelectric superlattices

piezoelectric superlattice is formed by intervallic polarizing oppositely along one direction in a piezoelectric solid. Due to the strong coupling between acoustic and electromagnetic behavior, Newton's equations of motion and Maxwell's equations have to be satisfied simultaneously. The polariton behavior in the superlattice is studied by plane-wave expansion method. Both band structure and field patterns are calculated. In the vicinity of the center of the first Brillouin zone, strong coupling of acoustic and electromagnetic energies are found in both passing and stopping bands. The kinetic, strain, electric, and magnetic energies of polariton are analyzed in detail. Correlation between energy allocation and field patterns is investigated.