Theory of nonlinear terahertz susceptibility in ferroelectrics

Abstract

An analytical theory is developed for predicting the nonlinear susceptibility of ionic polarization to continuous electromagnetic waves in both bulk and strained thin film ferroelectrics. Using a perturbation method for solving the nonlinear equation of motion for ionic polarization within the framework of Landau-Ginzburg-Devonshire theory, the full second-order nonlinear susceptibility tensor is derived as a function of frequency, temperature, and strain. The theory predicts the coexistence of a significantly enhanced second-order dielectric susceptibility and a relatively low dielectric loss in BaTiO3 films with a strain-stabilized monoclinic ferroelectric phase and in a strained SrTiO3 film near its temperature-driven second-order ferroelectric-to-paraelectric phase transition. This work establishes a theoretical framework for predicting and exploiting nonlinear interactions between THz waves and ferroelectric materials, and more generally, suggests exciting opportunities to strain-engineer nonlinear dynamical properties of ferroelectrics beyond the static and quasi-static limits.

References in corpus (7)

• Terahertz electric-field driven dynamical multiferroicity in SrTiO${}_3$
• Ultrafast terahertz-field-driven ionic response in ferroelectric BaTiO${}_3$
• Excitations of the ferroelectric order
• Ultrafast reversal of the ferroelectric polarization by a midinfrared pulse
• Background dielectric permittivity: material constant or fitting parameter?
• Analytical model and dynamical phase-field simulation of terahertz transmission across ferroelectrics
• Size effect of soft phonon dispersion law in nanosized ferroics

Cited by in corpus (2)

• Theory of terahertz pulse transmission through ferroelectric nanomembranes
• Strong coupling between coherent ferrons and cavity acoustic phonons