QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Lopa on January 14, 2020, 07:53

Title: WKB approximation
Post by: Lopa on January 14, 2020, 07:53

I am using QATK ver 2016.4 perpetual licence.

We have used Brenner (ASAP) potential parameter set for calculating the classical potential of a phonon (for SiNR and GeNR). Tersoff SiGe potential set is used with frozen phonon method. To calculate the phonon properties, i.e. forces and dynamical matrix 180 small displacements measuring 0.01 Ǻ are applied. The heat current is calculated considering the contribution of both electron and phonon. The transport calculations are carried out with the Landauer theory and the non-equilibrium Green’s function (NEGF) framework in Atomistix Tool Kit (ATK).

Is WKB approximation valid under such a scenario?

Title: Re: WKB approximation
Post by: Petr Khomyakov on January 16, 2020, 11:54

Quote from: Lopa on January 14, 2020, 07:53

I am using QATK ver 2016.4 perpetual licence.

Is WKB approximation valid under such a scenario?

How is this question related to QuantumATK? QuantumATK has no methodology based on a semiclassical WKB approximation. To the best of my knowledge, WKB has a very limited range of validity for modern electron (quantum) transport problems, where quantum effects are important.