Why solid-state harmonic models need femtosecond dephasing times · revision history
Revision 1
Accepted · first revision · record
- Title
- Why solid-state harmonic models need femtosecond dephasing times
- Plain
- Computer models of harmonic light from crystals only match experiments if the electrons lose their quantum phase within about a femtosecond. That is much faster than measured loss of phase in the same materials, and the cause is not agreed.
- Precise
- Semiconductor Bloch equation fits to solid HHG spectra require an interband dephasing time $T_2$ of roughly 1 to a few fs to produce clean harmonic peaks, while carrier dephasing measured by other ultrafast methods in the same crystals is much longer. Question: which physical process (spatial averaging over the focal intensity distribution, propagation, electron-electron scattering at high excitation, real-space trajectory interference) produces the apparent short $T_2$. An answer is a calculation with $T_2$ set by independent data that reproduces measured spectra, or the identification of the process that mimics short dephasing.
- Settled by
- A simulation with no fitted dephasing, including macroscopic propagation and focal averaging, that reproduces measured harmonic spectra and their contrast.
- Kind
- phenomenon
- Answer type
- mechanism
- References
- (empty)
- Literature status
- contested
- Status note
- Kilen et al. (Physical Review Letters 2020) showed that propagation effects can mimic fs dephasing; whether propagation, focal averaging or real-space trajectory interference accounts for the short $T_2$ in general is not agreed.
- Posed since
- (empty)