Fine structure and spin quantum beats in InP quantum dots in a magnetic field

The paper reports on quantum beats observed in the photoluminescence kinetics of a single layer of the InP self-assembled quantum dots in a magnetic field. It is found that the beats arise only after removal of excess charges from the quantum dots by an external electrical bias. The quantum beats are shown to be related to the interference of the excitonic fine-structure states split by the magnetic-field. The dependences of the beat characteristics on the magnetic-field strength and orientation are studied. Theoretical analysis based on a model spin Hamiltonian has allowed us to describe adequately the shape of the oscillating component of the signal. We have determined the values of the electron g-factor components and estimated the spread and the mean value of the hole g factor, as well as of the electron-hole exchange splitting parameters.