スピンカレントとは？
電流とスピンカレントと定義はOKだが、”電流が０のスピンカレント”となると分かりにくい。
magmatelab.imr.tohoku.ac.jp/Poster/LabPOSTER_spincurrent_01.pdf
“Charge current” (Je) is the flow of all the electrons with up- and down-spins (Je = J↑+ J↓).
On the other hand,“Spin current“ (Js) is the difference between the flows of the up-spin and down-spin electrons (Js = J↑- J↓).
Spincurrent is classified into two kinds of the spin currents: the “spin current with charge current” ..Je ≠ 0....and the“spin current without the charge current ..Je = 0...
When the electric current passes through a ferromagnet, the current is spin-polarized. (Fig. 1)
The injection ofthe spin-polarized current into a nonmagnet or a semiconductor induces spin accumulation at the interfacebetween the ferromagnet and the nonmagnet.
The region of the spin accumulation is related to the spin diffusionlength.
Figure 2 schematically illustrates the spin injection into a nonmagnetic wire from a ferromagnetic electrode.When the electric current flows between electrodes A and B, the spin accumulation occurs and the spin current with charge current flows in a nonmagnetic wire.
In addition, the spin current without the charge current flowsbetween electrodes A and C due to the diffusion of the spins.