(Color online) Phonon dispersion in GaAs, InAs, GaSb, and InP fitted with polynomial functions from experimental data of Refs. 20–24 , respectively. TA, LA, TO, and LO dispersion branches are identified by a circle, a diamond, a square, and a triangle, respectively.
(Color online) Temperature dependence of LO phonon lifetimes using the single mode relaxation time in GaAs (disks) and in InP (diamonds) with a single Grüneisen parameter to fit the experimental lifetimes of Ref. 2 (squares) and Ref. 4 (circles) dependencies, respectively. Curves are drawn to guide the eye.
Time evolution of the log of the zone-center LO phonon distribution with linear scales in GaAs. The crystal temperature is 300 K. The solid line is an asymptotic exponential decay slope joining the two extremes of the phonon distribution between 0 and 10 ps. This asymptote has a time constant of 60 ps.
(Color online) Time evolution of the first five wave-vector space discretization segments phonon perturbations in GaAs. Circles, squares, diamonds, and triangles are for phonons with wave-vectors amplitude close to 5.6 × 105 cm−1, 1.7 × 106 cm−1, 2.8 × 106 cm-1, and 3.9 × 106 cm−1, respectively. Crystal temperature is 300 K. Phonon distributions are initially driven out of equilibrium by the decay of photoexcited carriers.
(Color online) Time evolution of zone-center LO phonon perturbation in GaAs with strong initial deviations from equilibrium: Δn ∼ 15.7 (circles). Crystal temperature is 300 K. After a relatively long initial nonexponential decay, an asymptotic exponential decay (solid line) of ∼2.5 ps is recovered in both simulations. Dashed lines represent direct asymptotic exponential decays starting from the initial deviations from equilibrium, with a time constant of 2.5 ps.
(Color online) Time evolution of zone-center LO phonon perturbation in GaAs. Crystal temperature is 223 K (circles) and 77 K (diamonds). The lines are asymptotic exponential fits to the slope of decay yielding a time constant of ∼3.3 ps (solid line) and ∼6.6 ps (dotted line), respectively.
Zone-center LO phonon lifetime and relative contributions of the different decay channels. Phonon dispersion is taken along [ξ00] direction. Averaged results from calculations using dispersion relations along [ξ00], [ξξ0], and [ξξξ] are between parentheses.
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