  Over the past decade a large family of spintronic devices have been proposed
as candidates for replacing CMOS for future digital logic circuits. Using the
recently developed Modular Approach framework, we investigate and identify the
physical bottlenecks and engineering challenges facing current spintronic
devices. We then evaluate how systematic advancements in material properties
and device design innovations impact the performance of spintronic devices, as
a possible continuation of Moore's Law, even though some of these projections
are speculative and may require technological breakthroughs. Lastly, we
illustrate the use of the Modular Approach as an exploratory tool for
probabilistic networks, using superparamagnetic magnets as building blocks for
such networks. These building blocks leverage the inherent physics of
stochastic spin-torque switching and could provide ultra-compact and efficient
hardware for beyond-Boolean computational paradigms.
