  The need to find low power alternatives to digital electronic circuits has
led to increasing interest in alternative switching schemes like the magnetic
quantum cellular automata(MQCA) that store information in nanomagnets which
communicate through their magnetic fields. A recent proposal called all spin
logic (ASL) proposes to communicate between nanomagnets using spin currents
which are spatially localized and can be conveniently routed. The objective of
this paper is to present a model for ASL devices that is based on established
physics and is benchmarked against available experimental data and to use it to
investigate switching energy-delay of ASL devices.
