The G=0 term in electron-hole exchange interaction

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Xiaoming Wang
Posts: 67
Joined: Fri Dec 18, 2020 7:14 am

The G=0 term in electron-hole exchange interaction

Post by Xiaoming Wang » Tue May 11, 2021 8:52 pm

Hello,

In yambo implementation, to build the electron-hole exchange kernel V, the G=0 term is disregarded. However, from literatures, this term is responsible for the longitudinal-transverse splitting. I'm wondering why the G=0 term is omitted in the implementation.

Best,
Xiaoming Wang
The University of Toledo

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claudio
Posts: 375
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Re: The G=0 term in electron-hole exchange interaction

Post by claudio » Tue May 11, 2021 9:40 pm

Dear Xiaoming Wang

there is the possibility to include or exclude the G=0 in the BSE,
depending if you want only longitudinal or also transverse excitons
using the flag:

Lkind= "Lbar" # [BSE] Lbar (default) / full

in order to activate this flag use the verbosity -V resp when you generate the BSE input.


best
Claudio
Claudio Attaccalite
[CNRS/ Aix-Marseille Université/ CINaM laborarory / TSN department
Campus de Luminy – Case 913
13288 MARSEILLE Cedex 09
web site: http://www.attaccalite.com

Xiaoming Wang
Posts: 67
Joined: Fri Dec 18, 2020 7:14 am

Re: The G=0 term in electron-hole exchange interaction

Post by Xiaoming Wang » Tue May 11, 2021 10:14 pm

Dear Claudio,

Thanks for your quick reply.

Best,
Xiaoming Wang
The University of Toledo

Xiaoming Wang
Posts: 67
Joined: Fri Dec 18, 2020 7:14 am

Re: The G=0 term in electron-hole exchange interaction

Post by Xiaoming Wang » Thu Jun 24, 2021 12:18 am

claudio wrote:
Tue May 11, 2021 9:40 pm
Dear Xiaoming Wang

there is the possibility to include or exclude the G=0 in the BSE,
depending if you want only longitudinal or also transverse excitons
using the flag:

Lkind= "Lbar" # [BSE] Lbar (default) / full

in order to activate this flag use the verbosity -V resp when you generate the BSE input.


best
Claudio
Hi Claudio,

The G=0 term is direction dependent. for Lkind="full", which parameter controls the polarization direction? Is it BLongDir?

Best,
Xiaoming
Xiaoming Wang
The University of Toledo

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