Ferron-driven motion of non-collinear ferroelectric domain walls

We study the propagation of ferrons, the quanta of electric polarization waves, through a ferroelectric texture. We predict by analytic and numerical calculations that a $90^\circ$ domain wall (DW) operates as a beam splitter of longitudinal ferron and transverse optical phonon modes. An associated momentum-flux imbalance leads to forces that drive DW motion. In the weak-anisotropy limit, the DW becomes a rotating texture with nearly fixed-modulus, whose low-energy dynamics is described by a sine-Gordon equation. A ferron source then attracts the DW through a damping-induced force. Both driving forces scale linearly with incident wave intensity. Our results uncover qualitatively different routes to driven ferroelectric DW motion enabled by the vector nature of the polarization and offer functionalities for THz ferroelectric devices.