Spintronics—A retrospective and perspective

TLDR

Spintronics, a rapidly emerging field that exploits electron spin rather than charge, began as a DARPA program in 1996 focused on magnetic memory and sensors and has since expanded to include spin‑based semiconductor electronics. The authors review key spintronics developments and offer their perspective on the field’s future, focusing on areas they believe will drive significant technologies. The review examines spintronics progress, particularly the SPINS initiative that seeks to create semiconductor electronics based on electron spin. Spin‑polarized transport studies indicate the feasibility of a spin memory transistor that merges magnetic storage with amplification.

Abstract

Spintronics is a rapidly emerging field of science and technology that will most likely have a significant impact on the future of all aspects of electronics as we continue to move into the 21st century. Conventional electronics are based on the charge of the electron. Attempts to use the other fundamental property of an electron, its spin, have given rise to a new, rapidly evolving field, known as spintronics, an acronym for spin transport electronics that was first introduced in 1996 to designate a program of the U.S. Defense Advanced Research Projects Agency (DARPA). Initially, the spintronics program involved overseeing the development of advanced magnetic memory and sensors based on spin transport electronics. It was then expanded to included Spins IN Semiconductors (SPINS), in the hope of developing a new paradigm in semiconductor electronics based on the spin degree of freedom of the electron. Studies of spin-polarized transport in bulk and low-dimensional semiconductor structures show promise for the creation of a hybrid device that would combine magnetic storage with gain—in effect, a spin memory transistor. This paper reviews some of the major developments in this field and provides a perspective of what we think will be the future of this exciting field. It is not meant to be a comprehensive review of the whole field but reflects a bias on the part of the authors toward areas that they believe will lead to significant future technologies.