An improved structure for multilevel magnetoresistive random access memory

A new multilevel magnetoresistive random access memory (MRAM) has been developed. It consists of one sensing layer per storage layer. In this work, a MRAM with four different memory states has been demonstrated. With the NiFe/Cu/NiFeCo/Cu/NiFe/Cu/Co system, four distinguishable memory states can be obtained by applying a proper external magnetic field. It has been confirmed that the multilevel MRAM using pseudo spin valve MRAM mode alone can be established just with the adoption of one sensing layer per storage layer.