about Ni-Graphene-Ni MTJ device with a gate voltage

[grasim]

Hi, I have devoloped a Ni-Graphene-Ni MTJ device with a gate as the attachment. I try to study the spin-dependent properties of the Junction and then calculate the TMR vs gate voltage.  In the model, DFT and Neumann boundary condition are used. However, is the model reasonable? Can someone help me? Thank you.

[Anders Blom]

The main problem is that it's not really a interface structure anymore, it's more something like a Ni nanowire with a few carbon atoms in the middle. I can't see from the graph it there is periodicity out of the screen plane (I assume there is), so perhaps it's more like two thin Ni slabs with a nanoribbon in the middle.

The primary question is more perhaps if this corresponds to anything that has been (or could be) measured experimentally. If not it can of course still be an interesting exercise to compute it, but the results are perhaps less useful then.

[grasim]

Dear Anders Blom,
Many thanks for your answer and now I get what you mean. According to the present caulculation results, the TMR of this struture depends on the gate voltage. But this is not the question I meant to study.
The Ni-Graphene-Ni MTJ is an interface structure, in this case, what kind of model should I develop to consider the effect of an external electrical field on the TMR?
Should I use the model showed as x.jpg in the attachment, then how to deal with the external electrical field?
Thanks for your time, best regards.

The main problem is that it's not really a interface structure anymore, it's more something like a Ni nanowire with a few carbon atoms in the middle. I can't see from the graph it there is periodicity out of the screen plane (I assume there is), so perhaps it's more like two thin Ni slabs with a nanoribbon in the middle.

The primary question is more perhaps if this corresponds to anything that has been (or could be) measured experimentally. If not it can of course still be an interesting exercise to compute it, but the results are perhaps less useful then.