Dear ATK Experts
I am learning the calculation of spin transfer torque using ATK. I reproduced the tutorial magnetic carbon-chain device using the parameter "SpinTransferTorque", which evaluates the torkance in real space (denoted as tau_R here). I got the results the same as the tutorial, as shown in the attached figure (top pannels).
And I also try to use the parameter "calculateLinearResponseSpinTransferTorkance", which returns the atom-resolved torkance (denoted as tau_atom here). The results are shown in the bottom pannels of the attached figure.
The red dashed lines denote some atomic positions in the device. I found there are differences between the results from these two parameters, for examples: The maximums of tau_R and tau_atom have the opposite sign. And in some case, espacially for tau_y in the middle pannels, some peaks of tau_atom appear at the positions where the tau_R are not large.
So I have some questions about the two parameters
1. Why there are large differences between tau_R and tau_atom (the opposite sign, the different positons of maximums)? Which one should I trust?
2. I thought the maximums of tau_R should appear exactly at atomic positions. But at atomic positions tau_R curve shows a valley between two peaks appear above and below the atomic positions. Why do the peaks not appear at the atomic positions?
3. Can I qualitatively estimate the layer(atomic)-resolved torkance by averaging the peak values around the layer(atomic)-position?
I am using QuantumATK 2022-SP1.
Thank you very much!
