Four-State Anti-Ferroelectric Random Access Memory

Ferroelectric random access memory (FRAM) is a two-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 non-volatile memory based on anti-ferroelectric polycrystalline ceramics, termed anti-FRAM (AFRAM). The AFRAM memory cell architecture is similar to FRAM, but it is an operation protocol. Our initial experimental demonstration of the memory effect in anti-ferroelectric ceramic shows, remarkably, that the AFRAM technology encodes data in both ferroelectric sublattices of the anti-ferroelectric medium. This results in a four-state non-volatile memory capable of storing two digital bits simultaneously, unlike the FRAM technology that has two-memory states and it is capable to store one digital bit per cell.