Spin dynamics of electron with high excess energy in GaAs investigated by the simplified circularly dichromatic pump–probe model

sTime-resolved circularly polarized pump–probe spectroscopy is used to study the spin dynamics of electron with high excess energy in bulk GaAs at room temperature, an abnormal phenomenon that the curve taken from co-helicity circularly polarized pump–probe beam drops below the curve taken from cross-helicity circularly polarized pump–probe beam is observed. With both the spin-dependent band-filling and band-gap renormalization effects being taken into account, a simplified circularly dichromatic pump–probe model is further developed, the model can be used to fit the scanning experimental traces to retrieve the spin relaxation time, carrier recombination time, intensity coefficient of spin-dependent band-filling and band-gap renormalization effects, etc. With the parameters retrieved from the experimental data, the physical origin of the spectrum reversal can be explained in detail, both of the spin-dependent band-filling and band-gap renormalization effects contribute to the reversal spectrum.