QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: sathyajit on August 6, 2015, 06:10

Title: calculating band diagram along Y axis
Post by: sathyajit on August 6, 2015, 06:10
Hi,

I am trying to modify the script given in (By Dr.Anders)
http://quantumwise.com/forum/index.php?topic=1551.0

so that I can plot the band diagram along Y axis. I have marked the places where I replaced Z coordinates with Y coordinate in the script (please see attachment, the modifications are in
line 20 and line 124)
Can you please verify that this is correct ?

Also can you please tell me how do I calculate the band diagram along a specific line (set of atoms along a particular point in Z axis, with band diagram along Y axis) ?
I am thinking of using DOS calculation along a specific set of atoms and then using the obtained DOS in band diagram calculation.

Code
conf = nlread('device.nc',DeviceConfiguration)[0]

#setup energies
energies = numpy.linspace(-2,3,100) * eV

#calculate the dos from the Left electrode
dos = DeviceDensityOfStates(conf, energies=energies, contributions=Left)

#calculate the projections on the atoms in the central region
dos_projection = [
     dos.evaluate(projection_list = ProjectionList([i])) for i in range(3,11)
     ]

#plot the data
import pylab
pylab.figure()
for i in range(3,11):
    label = conf.elements()[i].symbol()+'('+str(i)+')'
    pylab.plot(
        energies.inUnitsOf(eV),
	dos_projection[i-3].inUnitsOf(eV**-1),
	label=label
	)
pylab.legend()
pylab.xlabel("Energy (eV)")
pylab.ylabel("dos (1/eV)")
pylab.show()

The above code calculates the DOS only on the left electrode, Is there a way to specify some atoms along the transport direction (Z axis in this case) ?
Title: Re: calculating band diagram along Y axis
Post by: sathyajit on August 9, 2015, 09:06
Pls reply.
Title: Re: calculating band diagram along Y axis
Post by: sathyajit on August 11, 2015, 13:00
Hi,

Can you please let me know if there is a possibility to do this ?
I saw the documentation but it appears the DOS can be calculated only along left or right electrode or average of device length
Title: Re: calculating band diagram along Y axis
Post by: Anders Blom on August 11, 2015, 15:13
Maybe what you really want to use is the LDOS instead though, because the DDOS is not spatially resolved. The way we achieve that is by projecting on atoms, layer by layer. If your structure is layered in Y, you can achieve they same, but you have to figure out which atoms that should belong to which layer, and then project on each group of atoms (each layer).