Electric field-driven dynamics of ferroelectrics and multiferroics is at the heart of their applications. While loss at GHz frequencies was seen in bulk ferroelectrics, the unambigous assignment of its origin was problematic until the recent spatially resolved measurements pinpointed that the loss is localized at domain walls [1]. We use phenomenological theory and first-principles calculations to model domainwall localized excitations and interpret recent scanning impedance microscopy measurements in hexagonal manganites and proper ferroelectrics as excitation of these localized vibrations.
References
[1] Xiaoyu Wu, Urko Petralanda, Lu Zheng, Yuan Ren, Rongwei Hu, Sang-Wook Cheong, Sergey Artyukhin, Keji Lai, Science Advances (accepted), arxiv:1702.06205