Thanks Joe! That was indeed the case! It became much closer with small a.
Best,
Ran
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Hi Ran, > I tried to compare KWANT’s results for transmission with
Datta’s ballistic transport formalism where total transmission is written
as > > Ttot=T(E)M(E) > > Here Datta takes T(E)=1 for ballistic transport
(please see: J. Appl. Phys. 105, 034506, 2009) and M(E) is the number of modes
in transverse direction. When I compared KWANT's results with Datta’s
expression, for the system given in “quantum_wire_revisited.py”, I
found different results (please see the attached figure where I tried to put
every relevant thing in the calculation). Since the reflectance is zero for
that system and so transmission is 1 for each mode, shouldn’t it give the
same results with Datta’s transmission expression? > Nice question!
Looking at your results it seems that the energies at which new modes open is
shifted with respect to Datta's result. I believe that this is simply due to
the fact that your discretization is not fine enough. Datta's result is
valid in the continuum limit, whereas the Kwant simulation (in the case
presented) uses a finite-difference discretization to render the problem
discrete. If you decrease the 'a' parameter, you should see the discrepancy
between the two result decrease. Happy Kwanting, Joe
