Question on implementing two spin currents with different polarization

[Sana Rao]

Hi, 

Is it possible to apply two different spin currents simultaneously, with one having spin polarization along the y direction and the other along the z direction, while allowing them to have different current densities(magnitudes)?

if this is possible, could you please let me know the recommended way to implement in mumax3?

[Josh Lauzier]

Hi,

The easiest way is to simply sum them together when applying the electric current density J. For instance, if you one spin current with a J=(0,Jy,0) and another J=(0,0,Jz), you can simply apply J=(0,Jy,Jz). The magnitudes of Jy and Jz are arbitrary.  Normally in mumax3 you don't set the spin current/spin polarization directly, it is mediated via J and the spin polarization Pol (which is just a scalar multiplier)

If for some reason this isn't possible you could do this with custom fields. A good example would be something like the SOT example in the mumax workshop session4. But most likely this isn't necessary. J currently isn't used for anything other than spin currents, so you can simply set J appropriately for the spin current profile you want.

Best,
Josh L.