Transmission analyzer

[bfazi]

Hi,
I calculated the I-V curve for a nanostructure and used the transmission analyzer to obtain the transmission eigenvalues. The question is, why the summation of the values for eigenvalues is more than the total transmission?
(the summation is equal to 4.7 while the total transmission is equal to 2.2).

[Anders Blom]

The eigenvalues are not supposed to sum up to T(E), they sum up to T(E,k). Then you integrate over k to get T(E).

[Anders Blom]

At zero temperature you would be right, however the default temperature broadening of the Fermi distributions of the two electrodes is 300 K, i.e. 25 meV, which brings in some finite transmission at this bias, from the looks of the curve.

[Anders Blom]

I don't see any issue with this. It is very common that the transmission eigenvalues differ a lot at the same energy, since the channels correspond to different symmetries etc. Actually you always have a very large number of them, but most are very close to zero, and we filter them out.