History-dependent filament configuration in multiterminal electrothermal memristors

Electrothermal memristors operate by a resistive switching mechanism based on Joule heating. During the switching process, metallic filaments form between the electrical contacts in a highly reversible and reproducible manner. Our experiments on planar VO₂-based devices show that multiple filaments can form when several electronic terminals are involved. The configuration, position, and size of the filaments depend sensitively on the applied inputs and on their history. Because of this history dependence and the interchangeability of the terminals, these devices are promising building blocks for programmable networks with built-in local memory.