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Updated: Jan 5, 2026

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing
Published on: December 3, 2013
Ultrafast acoustic phonon scattering in CH3NH3PbI3 revealed by femtosecond four-wave mixing
Samuel A March1, Drew B Riley1, Charlotte Clegg1
1Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
Abstract:
Carrier scattering processes are studied in CH3NH3PbI3 using temperature-dependent four-wave mixing experiments. Our results indicate that scattering by ionized impurities limits the interband dephasing time (T2) below 30 K, with strong electron-phonon scattering dominating at higher temperatures (with a time scale of 125 fs at 100 K). Our theoretical simulations provide quantitative agreement with the measured carrier scattering rate and show that the rate of acoustic phonon scattering is enhanced by strong spin-orbit coupling, which modifies the band-edge density of states. The Rashba coefficient extracted from fitting the experimental results (γc = 2 eV Å) is in agreement with calculations of the surface Rashba effect and recent experiments using the photogalvanic effect on thin films.
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