  The idea of nanomagnetic Boolean logic was advanced more than two decades
ago. It envisaged the use of nanomagnets with two stable magnetization
orientations as the primitive binary switch for implementing logic gates and
ultimately combinational/sequential circuits. Enthusiastic proclamations of how
nanomagnetic logic will eclipse traditional (transistor-based) logic circuits
proliferated the applied physics literature. Two decades later there is not a
single viable nanomagnetic logic chip in sight, let alone one that is a
commercial success. In this perspective article, I offer my reasons on why this
has come to pass. I present a realistic and tempered vision of nanomagnetic
logic, pointing out many misconceptions about this paradigm, flaws in some
proposals that appeared in the literature, shortcomings, and likely pitfalls
that might stymie progress in this field.
