A Feedback Spin-Valve Memristive System
  We propose theoretically a generalized memristive system based on controlled spin polarizations in the giant magnetoresistive material using a feedback loop with the classical Hall Effect. The dynamics can exhibit a memristive pinched hysteretic loop that possesses the self-crossing knot not located at the origin. Additionally, one can also observe a single-looped orbit in the device. We also provide a sufficient condition for the stability based on an estimation of the Floquet exponent. The analysis shows that the non-origin-crossing dynamics is generally permitted in a class of passive memory systems that are not subject to Ohm's Law. We further develop the prevailing homogeneous definition to a broadened concept of generalized heterogeneous memristive systems, permitting no self-crossing knot at the origin, and ultimately to the compound memory electronic systems. 
Weiran Cai, Torsten Schmidt, Udo J\"orges and Frank Ellinger
cond-mat.mes-hall cond-mat.mtrl-sci