  Polar textures have attracted significant attention in recent years as a
promising analog to spin-based textures in ferromagnets. Here, using optical
second harmonic generation based circular dichroism, we demonstrate
deterministic and reversible control of chirality over mesoscale regions in
ferroelectric vortices using an applied electric field. The microscopic origins
of the chirality, the pathway during the switching, and the mechanism for
electric-field control are described theoretically via phase-field modeling and
second-principles simulations, and experimentally by examination of the
microscopic response of the vortices under an applied field. The emergence of
chirality from the combination of non-chiral materials and subsequent control
of the handedness with an electric field has far-reaching implications for new
electronics based on chirality as a field controllable order parameter.
