Robustness of spin coherence of the exciton bound to neutral donor states in multilayer system.
We address the temperature influence on the precessional motion of electron spins under transverse magnetic field, studied in a GaAs/AlGaAs triple quantum well, using pump-probe Kerr rotation. In the presence of an applied in-plane magnetic field the TRKR measurements show the robustness of carrier's spin precession against temperature which can be easily traced in an extended range up to 250 K. Long-lasting spin coherence with dephasing time T2* > 14 ns was observed when the pump-probe wavelength was tuned to the exciton bound to a neutral donor transition. Furthermore, we observed that the increase of sample temperature from 5 K to 250 K, leads to a strong T2* reduction by almost 98%/97% for the excitation wavelengths of 823/821 nm. We show that the temperature increase not only causes the reduction of spin lifetime but can also lead to the variation of electron g-factor. Additionally, the spin dynamics was studied through the dependencies on the applied magnetic field and optical pump power.