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QuantumATK => General Questions and Answers => Topic started by: 89aj on August 17, 2017, 10:46

Title: Transmission Eigenstates - linear combination of the Bloch states
Post by: 89aj on August 17, 2017, 10:46

Dear QW and users,

I'm trying to identify and separate transmission eigenstates by similarity across energy and k-points. My issue is that if I have two eigenstates that contribute almost equally - in fact it changes across energy and k-points which one that contribute the most - I can't use the quantum number to identify them.

I was thinking that if I could get the e_a,n (the linear combination of Bloch states, http://docs.quantumwise.com/manuals/Types/TransmissionEigenstate/TransmissionEigenstate.html) then I could do the cross-product of the e_a,n vectors and similar eigenstates would be small compared to very different eigenstates.

So is it possible to get e_a,n?

I've tried the toArray method, but it is too heavy to save all eigenstates on a grid across many energies and k-points for such a comparison to be practical.

Maybe there is another way?

Thank you,
Anders

Title: Re: Transmission Eigenstates - linear combination of the Bloch states
Post by: Daniele Stradi on August 17, 2017, 13:49

Hi,

If I understood the question correctly, I do not think that what you propose is possible, because the transmission eigenchannels do not have the same symmetry as the Bloch states, see PRB 76 115117 (2007).

However, you can still calculate the transmission eigenstates for different energies and k-points, and then compare them directly.

Regards,
Daniele.

Title: Re: Transmission Eigenstates - linear combination of the Bloch states
Post by: 89aj on August 17, 2017, 14:34

Thanks Daniele.

Can you explain what you mean by comparing them directly?

Title: Re: Transmission Eigenstates - linear combination of the Bloch states
Post by: Jess Wellendorff on August 21, 2017, 10:06

You may plot them in 3D: https://docs.quantumwise.com/tutorials/atk_transport_calculations/atk_transport_calculations.html#transmission-eigenstates (https://docs.quantumwise.com/tutorials/atk_transport_calculations/atk_transport_calculations.html#transmission-eigenstates)

Title: Re: Transmission Eigenstates - linear combination of the Bloch states
Post by: Kim_W on December 16, 2017, 07:04

How to set k-point (ka and kb) in transmission eigenstates?

Title: Re: Transmission Eigenstates - linear combination of the Bloch states
Post by: Petr Khomyakov on December 16, 2017, 13:39

This can be done in the Calculator settings, see https://docs.quantumwise.com/tutorials/atk_transport_calculations/atk_transport_calculations.html.

Title: Re: Transmission Eigenstates - linear combination of the Bloch states
Post by: Kim_W on January 13, 2018, 14:00

There are three transmission values. How to choose it?

Title: Re: Transmission Eigenstates - linear combination of the Bloch states
Post by: Petr Khomyakov on January 17, 2018, 10:58

What do you mean by "How to choose it?"? For a given energy and k-point, there may exist several transmission channels, e.g., 3 like in your case. The graph for T(E) shows you the total transmission, which is the one of relevance for the actual conductance/current calculations.