A four-state memory can store four states in each memory cell. We designed a four-state memory cell using Co/PZT magnetoelectric composite and observed a broad magnetoelectric hysteretic output loop on applying magnetic field. Based on magnetoelectric hysteresis, we developed a read method by ap- plying a bias magnetic field on the memory cell. Results gave clearly four-state signals of 15.8, -4.4, 5.5 and -11.3 μV, which demonstrated the feasibility of our design.
