I do not know much about topological insulator. Maybe I'm wrong. <div><br></div><div>Yundi<br><div><br><br><div class="gmail_quote">On Sat, Oct 1, 2011 at 1:27 AM, Gerhard Fecher <span dir="ltr"><<a href="mailto:fecher@uni-mainz.de">fecher@uni-mainz.de</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">I guess you have some misconcept about spin, spin magnetic moments, magnetic moments, spin polarisation etc..<br>
<br>
There is no non-colinear magnetic moment in topological insulators<br>
<br>
What you have to calculate is the expectation value P=<Psi|Sigma|Psi*>/<Psi|Psi*> the for the Px, Py, Pz components of the spinpolarisation vector<br>
where Sigma are the Pauli spin matrices<br>
(consult the textbook "Polarized Electrons" by J. Kessler, Springer)<br>
<br>
Ciao<br>
Gerhard<br>
<br>
====================================<br>
Dr. Gerhard H. Fecher<br>
Institut of Inorganic and Analytical Chemistry<br>
Johannes Gutenberg - University<br>
55099 Mainz<br>
________________________________________<br>
Von: <a href="mailto:wien-bounces@zeus.theochem.tuwien.ac.at">wien-bounces@zeus.theochem.tuwien.ac.at</a> [<a href="mailto:wien-bounces@zeus.theochem.tuwien.ac.at">wien-bounces@zeus.theochem.tuwien.ac.at</a>]&quot; im Auftrag von &quot;Ruben Weht [<a href="mailto:ruweht@cnea.gov.ar">ruweht@cnea.gov.ar</a>]<br>
Gesendet: Freitag, 30. September 2011 23:49<br>
Bis: A Mailing list for WIEN2k users<br>
Betreff: Re: [Wien] spin texture?<br>
<div><div></div><div class="h5"><br>
Dear Yundi,<br>
<br>
Thanks for your reply.<br>
<br>
Well, really I do not know, that is part of<br>
my doubts....<br>
<br>
The spin texture is in reciprocal space.<br>
How can I manage that in real space?<br>
<br>
Ruben<br>
<br>
> Since the spin of the system changes like a spiral. The magnetic<br>
> moment is<br>
> non-collinear. The quantization axis changes. So it is necessary to<br>
> do a<br>
> non-collinear calculation.<br>
><br>
> Yundi<br>
><br>
> On Fri, Sep 30, 2011 at 1:24 PM, Ruben Weht <<a href="mailto:ruweht@cnea.gov.ar">ruweht@cnea.gov.ar</a>><br>
> wrote:<br>
><br>
>> Dear Wien users,<br>
>><br>
>> I am trying to reproduce some papers regarding the<br>
>> electronic structure of topological insulators<br>
>> and system with an important Rashba interaction<br>
>> (for instance BiTeI, Bi2Se3, etc).<br>
>><br>
>> On many of them people calculate the electronic band<br>
>> structure (on a slab for a topological insulator<br>
>> or in bulk for a Rashba system) and showed what<br>
>> is called "spin texture", a non-collinear spin<br>
>> arrangement along the resulting Fermi surface<br>
>> (most of the time near a Dirac cone).<br>
>> Almost all of those papers said that the electronic<br>
>> structure was calculated using Wien2k.<br>
>><br>
>> In general those system have a very strong<br>
>> spin-orbit coupling so, naively, I thought that<br>
>> spins up and down were completely mixed.<br>
>><br>
>> Does anyone know how to calculate/plot that<br>
>> property?<br>
>> Do I have to use the non-collinear code, Wienncm?.<br>
>><br>
>> Thanks a lot for your help,<br>
>><br>
>> Ruben<br>
>><br>
>> *===============================================*<br>
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>> | Departmento de Fisica - CNEA |<br>
>> | Avda. General Paz y Constituyentes |<br>
>> | 1650 - San Martin - ARGENTINA |<br>
>> | Email: <a href="mailto:ruweht@cnea.gov.ar">ruweht@cnea.gov.ar</a> |<br>
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<br>
*===============================================*<br>
| Ruben Weht |<br>
| Departmento de Fisica - CNEA |<br>
| Avda. General Paz y Constituyentes |<br>
| 1650 - San Martin - ARGENTINA |<br>
| Email: <a href="mailto:ruweht@cnea.gov.ar">ruweht@cnea.gov.ar</a> |<br>
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</div></div></blockquote></div><br></div></div>