analysis of zero bias result of a two probe device

[Jenny]

Hi, everyone.

I read the tutorial on the Au-DTB-Au device and found a question in the part of "Analysis of the zero-bias result".
https://www.quantumwise.com/documents/tutorials/latest/MolecularDevice/index.html/chap.analysis.html

Here, it mentioned that at Energy=2.4eV, T=1.45 when the calculation was performed with k=3*3 and k=21*21 gave T=1.58 at E=2.4eV. However, even with 21*21 mesh, the T value is still smaller than the sum of two dominating eigenvalues which gives a total transmission of 1.645. Does it mean that we need to increase the k-point sampling? Also, for the other two peaks at E=-3eV and E=-1.5eV, the summation of all transmission eigenvalues does not equal to the total transmission value at each energy level. Do we need to find the k mesh which is large enough to get us the summation of all transmission eigenvalues=total transmission value at each energy level?

Thank you very much.

Jenny

[Daniele Stradi]

Hi Jenny,

the short answer is yes. Please see the section "k-dependent transmission" in the same tutorial:
https://www.quantumwise.com/documents/tutorials/latest/MolecularDevice/index.html/chap.analysis.html#sect1.analysis.ktransmission