Nonlocal Spin Transport in Lateral Spin Valves with Multiple   Ferromagnetic Electrodes
  We study the nonlocal spin transport in a lateral spin valve with multiple ferromagnetic (FM) electrodes. When two current-injecting and two spin current-detecting electrodes are all ferromagnetic, the number of possible nonlocal spin signal states is four at maximum. In reality, this number is reduced, depending on the inter-probe distance and the relative magnitudes of the spin resistances. Our theoretical results are in agreement with recent experiments of spin injection into an Al island, a carbon nanotube, and graphene. 
Tae-Suk Kim, Hyun-Woo Lee, B. C. Lee