Time-resolved absorption changes at room temperature for LT-GaAs and for layers with different Mn concentrations. For clarity, the curves for successive values of are offset along the vertical axis, the preexcitation level of each curve corresponding to the equilibrium absorption. The arrow on each curve indicates the position of maximum absorption. The inset shows the sequence of pump and probe pulses for a positive time delay.
Time delay at which maximum absorption is observed and the recovery time of the induced absorption in as a function of Mn concentration .
Transient absorption changes at 80 K for GaMnAs D with at several probe photon wavelengths of 810, 830, and 860 nm, which is above, near, and below the band gap of the GaAs. The inset is the peak value of absorption changes from the band-filling effect and those from induced absorption.
(a) Coherent LO phonon oscillations at room temperature for LT-GaAs and layers with different Mn concentrations. (b) Phonon frequency and the dephasing rate in as a function of Mn concentration .
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