Study of Spin Current & Spin Field-Effect Transistors: A Paradigm Shift in Semiconductor Technology

Abstract

Paul Dirac indeed made significant contributions to physics, especially in merging quantum mechanics with Einstein's theory of relativity. This fusion resulted in the development of relativistic quantum mechanics, unveiling the concept of electron spin among other foundational principles. The exponential growth predicted by Moore's law accelerated the semiconductor and information industries, miniaturizing electronic components and integrating them into everyday devices. However, this rapid advancement faces limitations as transistor sizes approach the Nano-meter scale, reaching a point where a single transistor cannot be smaller than a single atom. Additionally, challenges like Joule heating due to finite-sized electronic devices pose obstacles to further miniaturization.  Spin, an intrinsic property of electrons, has been largely disregarded in everyday electronic products, except in specific instances such as magnetic materials or energy band degeneracy. This oversight presents an opportunity for the semiconductor industry through spintronics, a field that aims to leverage electron spin for developing a new generation of electronic devices. The discovery of giant magnetoresistance (GMR) in multilayer ferromagnetic thin films in 1988 marked a significant milestone, opening doors to a new era in electronics and materials science. This discovery introduced a new understanding of magnetoresistance in metals and further fueled the exploration of spin-related phenomena. The field of spintronics not only holds promise for the future of electronic devices but also impacts the information industry and offers new avenues for research in condensed matter physics and material science. Ultimately, despite electron spins being largely ignored in conventional electronics, their potential for revolutionizing technology and scientific understanding is immense.