Dear all,
I've looked for the previous mails about tunneling current
calculation, and find the mail as follow which say Traniesta is not suitable
for tiny tunneling current calculation.
I've used Transieta to get some results in my tunneling calculation.
The result is range from 0.01 pA to 1 pA , or 4.8*10^2 A/m^2 ~4.8 *10^4
A/m^2 , which is very tiny.
But the current results will varied greatly if I change the k-grid .
>From the transmission plot, I found that the magnitude is as small as 10^-4
and there are many peaks.
Could anyone tell me whether the results of Transiesta in tiny
tunneling current calculation is believable?
Thanks.
Holin Chen
RE: [SIESTA-L] Who can help me!
Jose A. Torres
Thu, 17 Jun 2010 08:57:42 -0700
Dear Mengqiu:
Transiesta is designed to give accurate
calculations of larger currents, it is designed
for the contact regime (as opposed to the tunneling
regime).
So it is not supposed to be accurate in the tunneling
regime because the description of the tunneling
barrier itself is not accurate, and the numerical
error is close to the values obtained
for that case.
You will certainly obtain some values for that
tunneling configuration, but use them at your
own risk!
My suggestion is to change the configuration
to try to make the tunneling regime as
"little tunneling" as possible (currents of about
100 nA per atom or larger) and try to conclude
the physics of the system from there.
Yours
Jose A.
