Perspectives on spintronics technology development: Giant magnetoresistance to spin transfer torque magnetic random access memory

Abstract

The discovery of the giant magnetoresistance (GMR) effect in 1988 started a new field called spintronics and was recognized with the 2007 Nobel Prize in Physics, which was awarded to Fert and Grunberg. Spintronics is based on the contribution of both electron spin and electron charges of materials to facilitate electronic functions, enabling one extra degree of freedom for device operations. Spintronics has grown rapidly during the past three decades with significant discoveries, technological advancements, and material and device developments that have led to numerous product applications. Furthermore, new research fields and technology areas have been discovered and continue to expand. In this Perspective, key technological advances in the field during the past three decades will be highlighted, starting with the developments that led to the first use of the GMR effect in hard disk drives and its impact in the spintronic ecosystem to currently used perpendicular magnetic tunnel junctions (pMTJs) for spin transfer torque magnetic random access memory (STT-MRAM) devices. The important aspects of the pMTJ characteristics for the application of STT-MRAM will be discussed. This Perspective will present perspectives on a new structure that enhances the efficiency of the pMTJ-based STT-MRAM and research directions that can drive further advances in spintronics.