Classical and quantum breathers: Application in photonics for ferroelectrics

Technologically, lithium tantalate is one of the most important ferroelectric materials with a low poling field that has several applications in the field of photonics and memory switching devices. Due to strong localization coupled with discreteness in a nonlinear K-G lattice, there is a formation of breathers and multi-breathers that manifest in the localized peaks across the domains in polarization-space-time plot. To probe the quantum states related to discrete breathers for the application in nano technology, the same K-G lattice is quantized to give rise to quantum breathers (QBs) that are explained by a periodic boundary condition. Secondly, in a non-periodic boundary condition, the temporal evolution of quanta shows interesting behavior as a function of impurity that is important from design viewpoint for the THz applications.