extracting full dielectric tensor
Moderators: Davide Sangalli, andrea marini, Daniele Varsano

 Posts: 11
 Joined: Thu Mar 28, 2019 10:53 am
extracting full dielectric tensor
Dear developers, I would like to ask if it is possible to obtain the full dielectric tensor tensor (or the its imaginary part) after having performed three calculations with independent polarizations. Thank you!
Dr. Michele Guerrini
HumboldtUniversität zu Berlin
Institut für Physik und IRIS Adlershof
Zum Grossen Windkanal 6, 12489 Berlin, Germany
email: guerrini@physik.huberlin.de
Skype: merlin__88
HumboldtUniversität zu Berlin
Institut für Physik und IRIS Adlershof
Zum Grossen Windkanal 6, 12489 Berlin, Germany
email: guerrini@physik.huberlin.de
Skype: merlin__88
 Daniele Varsano
 Posts: 2997
 Joined: Tue Mar 17, 2009 2:23 pm
 Contact:
Re: extracting full dielectric tensor
Dear Michele,
I think it should be possible by using yambo_kerr.
Maybe others can tell you more on that.
Daniele
I think it should be possible by using yambo_kerr.
Maybe others can tell you more on that.
Daniele
Dr. Daniele Varsano
S3CNR Institute of Nanoscience and MaX Center, Italy
MaX  Materials design at the Exascale
http://www.nano.cnr.it
http://www.maxcentre.eu/
S3CNR Institute of Nanoscience and MaX Center, Italy
MaX  Materials design at the Exascale
http://www.nano.cnr.it
http://www.maxcentre.eu/
 Davide Sangalli
 Posts: 412
 Joined: Tue May 29, 2012 4:49 pm
 Location: Via Salaria Km 29.3, CP 10, 00016, Monterotondo Stazione, Italy
 Contact:
Re: extracting full dielectric tensor
Dear Michele,
the standard version of yambo can compute the diagonal elements of the dielectric tensors. Playing with them, i.e. selecting different directions in input (you would need 6 in total), there are ways to reconstruct also the offdiagonal components of (the symmetric part of) the dielectric tensor. You can check in the literature for equations.
For the off diagonal components you can also use yambo_kerr, as mentioned by Daniele. Chosen a direction "d" in the "xy" plane in input, it will give epsilon_dd(w) and epsilon_{dd'}(w) where d' is a direction rotated by 90 degrees with respect to the original chosen. However it works only in the xy plane. Thus you need to rotate your sample (or change the code) to get also off diagonal terms which involve "z".
Notice that this approach, at variance with the previous one, would give also the antisymmetric part of the dielectric tensor if the material has any.
Hoep it helps.
Kind Regards,
Davide
the standard version of yambo can compute the diagonal elements of the dielectric tensors. Playing with them, i.e. selecting different directions in input (you would need 6 in total), there are ways to reconstruct also the offdiagonal components of (the symmetric part of) the dielectric tensor. You can check in the literature for equations.
For the off diagonal components you can also use yambo_kerr, as mentioned by Daniele. Chosen a direction "d" in the "xy" plane in input, it will give epsilon_dd(w) and epsilon_{dd'}(w) where d' is a direction rotated by 90 degrees with respect to the original chosen. However it works only in the xy plane. Thus you need to rotate your sample (or change the code) to get also off diagonal terms which involve "z".
Notice that this approach, at variance with the previous one, would give also the antisymmetric part of the dielectric tensor if the material has any.
Hoep it helps.
Kind Regards,
Davide
Davide Sangalli, PhD
CNRISM, Division of Ultrafast Processes in Materials (FLASHit) and MaX Centre
http://www.oldism.cnr.it/en/davidesangallicv/
http://www.maxcentre.eu/
CNRISM, Division of Ultrafast Processes in Materials (FLASHit) and MaX Centre
http://www.oldism.cnr.it/en/davidesangallicv/
http://www.maxcentre.eu/

 Posts: 62
 Joined: Fri Dec 18, 2020 7:14 am
Re: extracting full dielectric tensor
Hello,
Which equation is implemented to calculate the offdiagonal dielectric tensor for semiconductors? Eq. 22 or 23 of PRB 86, 125139 (2012)?
Best,
Xiaoming
Which equation is implemented to calculate the offdiagonal dielectric tensor for semiconductors? Eq. 22 or 23 of PRB 86, 125139 (2012)?
Best,
Xiaoming
Xiaoming Wang
The University of Toledo
The University of Toledo
 Davide Sangalli
 Posts: 412
 Joined: Tue May 29, 2012 4:49 pm
 Location: Via Salaria Km 29.3, CP 10, 00016, Monterotondo Stazione, Italy
 Contact:
Re: extracting full dielectric tensor
If you select
eq. (23) is used.
Instead with
eq.(22) is used
Best,
D.
Code: Select all
Gauge="length"
Instead with
Code: Select all
Gauge="velocity"
Best,
D.
Davide Sangalli, PhD
CNRISM, Division of Ultrafast Processes in Materials (FLASHit) and MaX Centre
http://www.oldism.cnr.it/en/davidesangallicv/
http://www.maxcentre.eu/
CNRISM, Division of Ultrafast Processes in Materials (FLASHit) and MaX Centre
http://www.oldism.cnr.it/en/davidesangallicv/
http://www.maxcentre.eu/

 Posts: 62
 Joined: Fri Dec 18, 2020 7:14 am
Re: extracting full dielectric tensor
Thanks Davide,
For the velocity gauge, it seems the velocity operator need to be renormalized as explained in your paper PRB 95, 155203 (2017). I'm wondering why the position operator need not to be corrected?
Best,
Xiaoming
For the velocity gauge, it seems the velocity operator need to be renormalized as explained in your paper PRB 95, 155203 (2017). I'm wondering why the position operator need not to be corrected?
Best,
Xiaoming
Xiaoming Wang
The University of Toledo
The University of Toledo