Understanding spintronics in F/N/F structures through a mechanical analogy

A mechanical equivalent system is introduced to mimic the behavior of multilayer structures with diffusive spin transport. The analogy allows one to use existing mechanical intuition to predict the influence of various parameters on spin torques and spin-dependent magnetoresistance. In particular, it provides an understanding of the sign-changing behavior of spin torque in asymmetric F/N/F spin valves. It further helps to uncover the physical reason behind the singular behavior of spin magnetoresistance in devices with ultra-thin N-layers.