[Wannier] Postw90 and Berry curvature origin

[David Vanderbilt]

Vahid,

The details are probably complicated, but probably the short answer
is that Fe is a centrosymmetric collinear magnet.  In this case
the Berry curvature vanishes everywhere in the BZ in the absence
of SOC.  Roughly, the SOC goes like L.S which does have an (Lz Sz)
spin-diagonal component, but typically the (L+ S-) and (L- S+)
spin-mixing terms are more active.

I hope this helps a little...

David


On Wed, 3 Jan 2024, Vahid Askarpour wrote:

> Dear Wannier90 Users,
>
> Looking at the postw90 background paper (PRB74, 195118, 2006), in Fig. 3a, there is a large spike and several small spikes for the Berry curvature in Fe. The large peak is attributed to spin-orbit coupling with states above and below E_F. However, both small and large peaks produce small energy denominators in Eq. 31. This might be obvious to many but  why is the peak due to spin-orbit much larger than the other peaks?
>
> Thanks,
> Vahid
>
> Vahid Askarpour
> Department of Physics and Atmospheric Science
> Dalhousie University,
> Halifax, NS
> CANADA
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>

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