4-state anti-ferroelectric random access memory

Ferroelectric random access memory (FRAM) is a 2-state non-volatile memory, in which information is digitally encoded using switchable remanent polarization states within a ferroelectric thin film capacitor. Here we propose a novel nonvolatile memory based on anti-ferroelectric polycrystalline ceramics, termed anti-ferroelectric random access memory (AFRAM). The AFRAM memory cell architecture is similar to FRAM, but it requires a more complex operation protocol. Our initial experimental demonstration of the memory effect in antiferroelectric ceramic shows, remarkably, that the AFRAM technology encodes data in both ferroelectric sublattices of the anti-ferroelectric medium. This results in a 4-state non-volatile memory capable of storing 2 digital bits simultaneously, unlike the FRAM technology that has 2-memory states and it is capable to store 1 digital bit per cell.