Terahertz Electrodynamics of 180◦ Domain Walls in Thin Ferroelectric Films

Igor Lukyanchuk, 2 Alexey Pakhomov, 3 Anäıs Sené, Alexandr Sidorkin, and Valerii Vinokur University of Picardie, Laboratory of Condensed Matter Physics, Amiens, 80039, France Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA Department of Experimental Physics, Voronezh State University Voronezh 394000, Russia We investigate oscillation dynamics of a periodic structure of the 180◦ domain walls in nanometricaly thin substrate-deposited ferroelectric films and superlattices. We calculate dynamic permittivity of such structures and reveal a collective resonance mode, which in the typical ferroelectric compounds, PbTiO3/SrTiO3, lies in the suband low THz frequency range of 0.3 ÷ 3 THz. We propose the reflection-absorbtion spectroscopy experiments to observe this mode.