Phonon–polariton in a piezoelectric superlattice

In a series of works Zhu et al. [Phy. Rev.Lett. 90 (2003) 0532903] have investigated the possibility of acoustic polaritons in a novel superlattice system consisting of piezoelectric materials. In the present work that two excitations are pointed out are: one due to piezo polaritons and the other due to the optic phonon mode. The behavior of the photonic gaps as a function of superlattice period is investigated systematically.