Transport properties of a zigzag nanoribbon tutorial

[simCity]

Hi,

I replicated the zigzag GNR tutorial (Transport properties of a zigzag nanoribbon) and obtained the same results. However, I'm a bit confused. Because I came across a paper mentioning spin-resolved bandstructures and bandgaps for ZGNRs (http://www.nature.com/nature/journal/v444/n7117/abs/nature05180.html). Is it possible to obtain spin-dependent bandstructure of the GNR in the tutorial in ATK? There seems a bandgap when spin-polarized bandstructure is drawn according top this paper.

Thanks in advance...
Jimmy

[kstokbro]

This is correct, to learn how to do the spin polarized calculations check:
http://www.quantumwise.com/documents/tutorials/latest/GrapheneBloch/index.html/

Let us know if this is sufficient to get you started on the spin polarized transport calculations

[simCity]

Thanks for the reply.

In the mentioned tutorial on page 8, BlochState dialog box has the optin "None" for the spin but in ATK 12.8 there are only spin up and down options there. How can I replicate the tutorial since when I select spin up or down, the resulting states are different from those given on page 10?

Best
Jimmy 

[Anders Blom]

Use Spin.Up. We are working on updating the tutorial for ATK 13.8, the pictures may differ slightly but the ideas are the same still.

[simCity]

I also did the polarized and unpolarized transmission spectrum calculations as attached. Spin up and down transmissions are different as can be seen from fig 1 although bandstructure of up and down stated were overlapped as in the tutorial. Why up and down transmissions are different and what's the relation of them to the unpolarized transmission shown in the latter figure. Thanks a lot.

Note: And how to decide to include spin polarization for a device? Is it just try spin polarized and not and compare each other?