Pure spin current vs. spin-polarized charge current?

[sokrates]

Is there anyone who understands (or has ever heard of) the difference between a pure spin current and a spin-polarized charge current?

It causes a great deal of confusion for me, because I cannot imagine a current flowing without an accompanying charge flow... Guesses and conjectures are welcome. I have been struggling about this for quite some time now.

Here's the paper and the context if you are interested in learning more:
(hopefully you have a Nature subscription)

http://www.nature.com/nphys/journal/v4/n11/full/nphys1095.html

 

[sokrates]

bump.

I don't want to believe that nobody has even an opinion on this!