QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: AsifShah on June 5, 2023, 11:15

Title: Transmission with Different electrodes
Post by: AsifShah on June 5, 2023, 11:15

Dear Admin,
I want to calculate zero-bias transmission with different electrodes. I am not an expert at Quantum Transport but will the transmission spectrum depend on the direction of transmission i.e from left to right electrode or right to left electrode?

And how does ATK calculate zero bias transmission?
And how to calculate transmission from left to right and right to left?

Title: Re: Transmission with Different electrodes
Post by: ulrich_poto on January 25, 2024, 10:29

I would second that!

Title: Re: Transmission with Different electrodes
Post by: Anders Blom on January 26, 2024, 20:53

Zero bias really just means no external bias. If the two electrodes are different, they will have different Fermi level and thus an internal bias still exists. So there is no special treatment of this case, the calculations proceed as for any device, except that the crucial in which the two Fermi levels are brought into alignment (no bias!) results in a shift of the bands in one electrode, and a current will flow from occupied to unoccupied bands (but backwards, since current is opposite electron flow). That is why left-right and right-left currents might differ in this case.

Title: Re: Transmission with Different electrodes
Post by: AsifShah on February 4, 2024, 05:55

Thanks for your response.

I am facing a convergence issue in non-zero bias transmission. I tried reducing pulay mixing, history steps but nothng is helping.
Can I have your email ID so that I can share my file?