lifetime comparison

[kazemoor]

Dear friends

I know that Yambo can calculate quasiparticle lifetime which is directly comparable with 2PPE experimental results. But I don't know how it relates to experiments like Transient photoconductance measurements which give the lifetime of photocarriers . Is it same as quasiparticle lifetime or it is comarable with excitonic lifetime? or with recombination lifetime?

In special case:
We all know that people are interested in enhancement of activity of TiO2 for both anatase and rutile phases which is determined by e-h pair lifetime . For example the e-h pair lifetime of anatase is 10 ns in Transient photoconductance measurment . is e-h pair lifetime similar with exciton lifetime or not? Is it any way to compare e-h lifetime data with quasiparticle lifetime obtained with yambo?
In other word, is it possible to determine the reacitvity of TiO2 with quasiparticle lifetime or not?
And finally, does yambo calculate exitonic lifetime ? If yes, how?

Any help is greatly appreciated.


Ali Kazempour, Physics Dept, PNU university, Tehran , Iran

[Daniele Varsano]

Dear Ali,
the QP quasiparticle lifetime calculated by Yambo, is the lifetime of a charged excitation (elctron addition/remotion) that can be somehow
compared with linewdith of band structures (I think!). 2PPE measure lifetimes of a neutral excitation, ie the lifetime of the electron excited form the first photon, measuring the population in that states in time by photoemission, so as you said, it is the lifetime of an excited states (exciton). Actually Yambo does not calculate this lifetimes, even if people are working on that subject, but it is in phase of development and it is not previewed to include that part
in the next releases of Yambo in short time. Anyway may be Dr. Marini can give you a more rigorous answer to your question.

Best,

Daniele

[kazemoor]

Dear Daniele
Would you please introduce good reference where discuss with more detailes about quasiparticle lifetime and Z (renormalization factor)of semiconductors?

Thanks a lot

Ali Kazempour, Pysics Dept., PNU University, Tehran, Iran

[Daniele Varsano]

Dear Ali,
in the review by Aryasetiawan and Gunnarson you can surely find some discussion on that.
The check also other reviews listed in the documentation of the yambo web pages.
Hope it helps,

Best,

Daniele