lifetime calculation

[haseebphysics1]

Dear Daniele,

Is the lifetimes of electrons and holes are possible to calculate in the latest available version of Yambo?

In a photocatalyst system, I want to make separation time of electrons (in CB) and holes (in VB) as large as possible by means of doping or something else. Therefore, if the e-h lifetime calculations not implemented so far, then,
can electrons QP GW lifetime help? because if electrons lifetime of excitation is made somehow larger then I can guess the holes will also be available in VB for larger extent of time?


Regards,
Haseeb Ahmad,
LUMS, Pakistan

[Daniele Varsano]

Dear Haseeb,

lifetime calculations are implemented as described in sec 4.2 of the yambo paper:
https://iopscience.iop.org/article/10.1 ... 48X/ab15d0

An example can be found here:
http://www.yambo-code.org/tutorials/Rea ... /index.php

Best,
Daniele

[plasmon]

It seems that Yambo uses the KS-state database to calculate the lifetimes for each electronic state. It is possible to calculate the lifetimes for electrons based on the GW-PPA calculations?Thank you!

Hao

1-for Al case ,before doing any GW calculation, yambo -l give us mass-shell (z=1) lifetimes. Is it true ?

Yes. It is true.

2- why some of electronic excitation lifetimes are negative. what does it mean? or is it the convention of the code which prints with negative sign?

Yambo uses the convention that at zero temperature the imaginary part of the self-energy changes sign accross the Fermi Level and the lifetimes do the same.

3- For metals, near the Fermi energy, the el-ph scattering is also important. is it possible to take into account the contribution of el-ph scattering lifetime using electron-phonon tutorial section in yambo?

The way Yambo computs e-p interaction is too complicated at the moment due to the fact that the interface with QE is out-of-date. We are working on this and in the new release of Yambo the e-p interaction should be fully working.

Andrea

[Daniele Varsano]

Dear Hao,
lifetimes calculated in plasmon-pole calculations are meaningless and you need to resort to a full-frequency description.
This is done as described in Sec.4.2 of the last yambo reference paper.

Best,
Daniele