Yambo Community Forum

Hi there,
Is there any possibility to calculate el-hole pair lifetime in YAMBO code?
Best
S. Ataei, University of Tehran, Iran

Dear S. Atei,
at the moment it is not possible to calculate it.
Kind regards,
Daniele

Dear Daniele,
Thanks a lot.
But another question
Are the results of lifetime calculation (in yambo)
for semiconductors reliable and in good agreement with
experiment?
Best regards
S. Ataei, University of Tehran, Iran

Dear Atei,
comparison with experiment is always a delicate issue: depending on the system, are all the physical effects included in the theory?
For instances, depending on the system, electorn-phonon contribution could be relevant (please note that el-ph part of yambo is temporarily unavailable).
In any case I suggest you to have a look to this paper by Marini et al. on calculation of lifetimes done using yambo:
http://www.yambo-code.org/papers/cu-lifetimes.pdf

Best,
Daniele

Dear Daniele,

1) Does yambo take into account the real part of Z factor like equation 5 in the paper you mentioned above or ONLY the imaginary or sum of real and imaginary part of Z factor (Re Z + Im Z) for calculation of quasi particle life times ???

2) Why are in the paper in equations 3 and 4 self energy and Z factor given at quasi particle energies, i thought it should be at DFT energies, as you get Z factor when expanding sigma (omega=QP) around DFT energies !!!


Bests
Vito

Dear Vito,
1) I suppose only real part is considered.
2) Because you consider as starting qp point the E_qp^0 and do the expansion. When you consider the KS energies as first guess, you will have Z=1 and obtain the on-mass-shell GW expression for the lifetime:
tau=1/(2 Im \Sigma (E_KS))

Best,
Daniele