Fig. 4: Computational simulation of domain boundary movement.

Energy barrier of simulated a tail-to-tail and b head-to-tail domain boundary shift. c Dependence of the energy barrier on the external electric field, where the energy barrier was calculated by the energy difference between the transition state and the initial state in (a, b). d Map of the out-of-plane dipole moment of the middle Se atom sampled inside the green hexagon. The corresponding atomic structures of the transition states of the tail-to-tail and head-to-tail domain boundaries are shown in blue and red rectangles, respectively. Green arrows in all atomic structures indicate the directions of the in-plane electric polarization. The black arrow indicates the out-of-plane electric polarization.