QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: qiuweicheng on January 3, 2017, 06:36

Title: how to transform the picture of k-depended transmission
Post by: qiuweicheng on January 3, 2017, 06:36

The device structure is Ni/Graphene/Ni, as shown in picture 1, the angle between axis A and axis B is 120。The  brillouin zone of left electrode, middle region and right  electrode are similar, as shown in picture 2, it is a hexagonal structure. However, the the picture of k-depended  transmission is shown in picture 3, it is a square structure.
The question: in the brillouin zone, there is KA and KB axis. In the  picture of k-depended  transmission,  there is also KA and KB axis. What is the relationship between these two coordinated system? How to transform the  picture of k-depended  transmission into the required picture, the required picture is a  hexagonal structure which contains only the first  brillouin zone.

Title: Re: how to transform the picture of k-depended transmission
Post by: Daniele Stradi on January 4, 2017, 09:41

KA and KB indicate the same coordinate system in both plots. 

The data you show contain the first Brillouin zone, but unfortunately at the moment the transmission analyzer does not support plotting of hexagonal Brillouin zones.

If you right-click on the image you can export the data as a standard ASCII file, and then plot these data using an hexagonal structure. Notice that KA and KB are expressed as reciprocal coordinates, so in order to plot the hexagonal Brillouin zone, you should express them in Cartesian coordiantes. you can do the following:

(i) retrieve the Bravais lattice from the device configuration:
http://docs.quantumwise.com/manuals/Types/DeviceConfiguration/DeviceConfiguration.html

(ii) get the reciprocal vectors of this Bravais lattice:
http://docs.quantumwise.com/manuals/includes/BravaisLattices.html#NL.CommonConcepts.Configurations.BravaisLattice.BravaisLattice

Title: Re: how to transform the picture of k-depended transmission
Post by: Anders Blom on January 4, 2017, 10:47

I have a script that can do it, but it is a bit old so I need to check if it's compatible with 2016 or some small adjustments are necessary (for spin, mainly).

Title: Re: how to transform the picture of k-depended transmission
Post by: qiuweicheng on January 6, 2017, 04:03

Thank you for your reply.  Hi,  Anders Blom.   After you check the script, could you  please sent it to me in time?  thank you very much.

Title: Re: how to transform the picture of k-depended transmission
Post by: Anders Blom on January 10, 2017, 00:37

There were a few changes in Matplotlib also...
Attached in two versions, with an example that runs in ATK 2016.
First run graphene.py to make graphene.nc, then try the two plot scripts.

Title: Re: how to transform the picture of k-depended transmission
Post by: qiuweicheng on January 10, 2017, 06:04

OK, thank you very much ;D