QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: bfazi on July 4, 2017, 18:34

Title: Tunnelling FET
Post by: bfazi on July 4, 2017, 18:34

Hello,

I want to know, how does ATK work when we design a tunnelling FET? As I know, to calculate the current in TFET, we need to consider WKB approximation to model the tunnelling barrier but I do not know that ATK considers this approximation or not? If yes, is there any references that I can refer to it.

Many Thanks

Title: Re: Tunnelling FET
Post by: Petr Khomyakov on July 4, 2017, 23:25

The ATK transport calculations are not based on the WKB approximation. The ATK solves the scattering problem in an numerically-exact manner, using Green's-function formalism; you may take a look at http://docs.quantumwise.com/manuals/NEGF.html and http://docs.quantumwise.com/tutorials/atk_transport_calculations/atk_transport_calculations.html for more details on the issue.

Title: Re: Tunnelling FET
Post by: Anders Blom on July 4, 2017, 23:42

Just to be clear,

Quote from: AHB on July  4, 2017, 18:34

to calculate the current in TFET, we need to consider WKB approximation to model the tunnelling barrier

is not an accurate statement. The WKB approximation is one possible way to model the tunneling barrier, but there are other ways too, like the NEGF method used in ATK.

Title: Re: Tunnelling FET
Post by: Petr Khomyakov on July 5, 2017, 17:36

To emphasize, the WKB approximation-based approach is, in general, also less accurate compared to the NEGF-based approach implemented in the ATK.