How Does ARPES Measure the Lifetime of Injected Photo Holes?

[fk08]

Why it is said that ARPES measures the lifetime of the injected photo hole?
When photons with certain energy promote electrons from the initial state to the final state with kinetic energy then by knowing the photon energy one can simply determine the binding energy of the initial state: Eb = hv - Ekin - W(orkfunction).

I do not see the connection to the hole lifetime.

 

[ZapperZ]

Why it is said that ARPES measures the lifetime of the injected photo hole?
When photons with certain energy promote electrons from the initial state to the final state with kinetic energy then by knowing the photon energy one can simply determine the binding energy of the initial state: Eb = hv - Ekin - W(orkfunction).

I do not see the connection to the hole lifetime.

You can't get it that way.

What you need to do is look at the energy distribution curve (EDC) of the ARPES spectrum at a particular momentum. This represents what we call the spectral function, A(k,w), at that particular k value. If this is a regular, Fermi-liquid-type quasiparticle, there will be a well-defined peak in the spectrum that closely resembles a Lorentizian. The width of that peak (or full-width at half maximum) corresponds to the inverse-lifetime of the quasiparticle, or photo-hole.

See, for example, Valla et al., Science v.285, p.2110 (1999).

Zz.