Fig. 4: The effect of flexoelectricity on topological details of moiré vortex patterns.
From: Strain-induced moiré polar vortex in twisted paraelectric freestanding bilayers
IP vorticity (a) and OP polarity (b) at positions A and B, dependent on shear flexoelectric coefficients, vary from 1 to 3 V. c–j IP divergence under the modulation of longitudinal flexoelectric coefficients of bottom surface vortex, where f44 was set as 3 V. The size of a single vortex is 2 nm. h IP divergence under the equal effect of longitudinal and transversal flexoelectricity. i, j IP divergence and OP polarity as a function of the net value of longitudinal and transversal flexoelectric coefficients f11−f12. varies from −6 to 6 V.
