Author Topic: transmission spectrum  (Read 8251 times)

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Offline qnsyhanjiu

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transmission spectrum
« on: March 25, 2011, 03:41 »
Now,I use the 2008.10 atk.I want to plot the transmission spectrum,when I add the spin,how can I plot the spin up and spin down, and when use the An electrode,how can I add spin? For example,the Initial Scaled Spin how  to set up?

Offline zh

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Re: transmission spectrum
« Reply #1 on: March 25, 2011, 03:55 »
In the manual of ATK2008.10, there is a good tutorial for the spin-polarization of a two-probe system:
http://quantumwise.com/documents/manuals/ATK-2008.10/chap.twoprobespin.html

Please refer to it for the spin setup of a two-probe system.

The spin setup of the electrodes in  a two-probe system is specified by calling:
ElectrodeParameters(
...
electron_density_parameters=electronDensityParameters(
...
initial_scaled_spin =[x,x,x,..,x]
...
)
...
)

For the spin-dependent transmission spectrum, there is a simple example given in the manual to illustrate how to print out the spin-up and spin-down spectra:
http://quantumwise.com/documents/manuals/ATK-2008.10/ref.calculatetransmissionspectrum.html
« Last Edit: March 25, 2011, 04:11 by zh »

Offline qnsyhanjiu

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transmission spectrum
« Reply #2 on: March 26, 2011, 13:39 »
When I  plot the transmission spectrum, the ATK whether has been do the 0 point as the fermi energy? AND how to make the plot more  Smooth ?

Offline zh

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Re: transmission spectrum
« Reply #3 on: March 26, 2011, 13:52 »
For the first question, the answer is yes. 

You can use smaller energy separation for the energy axis (i.e., more dense energy points) in the calculation of transmission spectrum.

Offline qnsyhanjiu

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Re: transmission spectrum
« Reply #4 on: March 27, 2011, 10:35 »
when I plot the transmission spectrum,I add the spin,which other Paramaters need set up in order to make the result much more precise.

Offline qnsyhanjiu

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Re: transmission spectrum
« Reply #5 on: March 27, 2011, 10:49 »
Thank you very much!

Offline zh

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Re: transmission spectrum
« Reply #6 on: March 27, 2011, 10:57 »
There are several parameters, e.g.,:
1) the size of k-mesh in brillouinZoneIntegrationParameters();
2) the basis_set_parameters;
3) the mesh cut-off in electronDensityParameters.

Please refer to the tutorial:
http://quantumwise.com/documents/tutorials/latest/Fe-MgO-Fe/Fe-MgO-Fe.pdf

Offline qnsyhanjiu

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Re: transmission spectrum
« Reply #7 on: March 28, 2011, 12:17 »
When I plot the transmission spetrum,the peak value is very tip,how can I make it smooth? Are there some parameter can be set up to make smooth? Thank you very much!


Offline qnsyhanjiu

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Re: transmission spectrum
« Reply #8 on: March 31, 2011, 12:56 »
I plot the transmission spectrum,when I raise the electrode temperature, if the transmission spectrum will be more smooth?

Offline zh

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Re: transmission spectrum
« Reply #9 on: April 1, 2011, 16:37 »
I plot the transmission spectrum,when I raise the electrode temperature, if the transmission spectrum will be more smooth?
The increasing of electrode temperature does not help. Try the use of more dense k-mesh in the calculation of transmission spectrum.

Offline qnsyhanjiu

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Re: transmission spectrum
« Reply #10 on: April 3, 2011, 04:18 »
Thank you very much! Except for using more dense k-mesh ,if I can use more history steps to make the transmission spectrum to smooth?

Offline zh

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Re: transmission spectrum
« Reply #11 on: April 3, 2011, 04:32 »
Except for using more dense k-mesh ,if I can use more history steps to make the transmission spectrum to smooth?
The use of more history steps also cannot make smoothing the transmission spectrum.

Offline qnsyhanjiu

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Re: transmission spectrum
« Reply #12 on: April 4, 2011, 14:15 »
When I computer the transmission spectrum,it need too much time ,how can make it quickly and self-consistent?