[Pw_forum] pwcond with spin-orbital effect

[Gabriele Sclauzero]

xirainbow wrote:
> Dear all：
> 
> I know the example 22 give a transmission with spin-orbital effect.
> 
> Is the spin-orbital effect considered as perturbation？

No, it is not correct to say this in my point of view. The SO effect is included through 
the use of so-called fully-relativistic pseudo potentials, as it is done in PWscf (see 
Andrea Dal Corso and Adriano Mosca Conte, Phys. Rev. B 71 115106 (2005) for details).

> Does the pwcond.x use "Green function" method?

No, it uses a scattering state approach, which integrates numerically a scattering 
equation in real space along the direction of transport (while in the perpendicular 
directions the PW basis of the PWscf calculation is retained).
See:
Hyoung Joon Choi and Jisoon Ihm, Phys. Rev. B 59, 2267 (1999)

for the method originally developed for norm-conserving PPs and:
Andrea Dal Corso, Alexander Smogunov, and Erio Tosatti, Phys. Rev. B 74, 045429 (2006)

for the extension to US-PPs with spin-orbit coupling.

> Can the pwcond.x deal with "voltage bias" condition?

No, it is built within the Landauer-Buttiker linear response theory, which gives the low 
bias limit of the conductance.

Regards,

GS

> 
> Thanks in advance：）
> 
> -- 
> ____________________________________
> Hui Wang
> School of physics, Nankai University, Tianjin, China
> 
> 
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