Strain-mediated multilevel ferroelectric random access memory operating through a magnetic field

Abstract

Ferroelectric random access memory (FeRAM) is based on the physical movement of atoms in response to external fields, and have lower power consumption and faster writing performance than conventional flash memory. However, the wide application of current FeRAM is limited by its low storage density. Here we demonstrate, using phase field simulations, a new pathway towards high-density multilevel FeRAM that exhibits significant improvement over the one level FeRAM technologies. The proposed multilevel FeRAM devices employ strain-mediated multiple vortex states of polarization to store more information, which is based on the novel switching behavior between the single and triple vortex states under a time-dependent magnetic field. The FeRAM can store two bits per cell via four stable vortex states of polarization. As a consequence, the areal bit densities of the polarization vortex states of the FeRAM can be two times higher than those of the one level FeRAM employing a single vortex state of polarization.