Cooperative Response of Pb(ZrTi)O3 Nanoparticles to Curled Electric Fields

We investigate cooperative responses, as well as a microscopic mechanism for vortex switching, in Pb(Zr0.5Ti0.5)O-3 nanoparticles under curled electric fields. We find that the domain coexistence mechanism is not valid for toroid switching. Instead dipoles display unusual collective behavior by forming a new vortex with a perpendicular (not opposite) toroid moment. The correlation between the new and original vortices is revealed to be critical for reversing the toroid moment. We further describe a technological approach that is able to drastically reduce the curled electric field needed for vortex switching.