Energy dispersion and 3D magnetic anisotropy of electron and hole g-factors in (In,Ga)As/GaAs self-assembled quantum dots

The electron and hole Larmor spin precession was studied by time-resolved pump-probe Faraday rotation on an inhomogeneous ensemble of singly-charged self-assembled quantum dots. Dependence of electron g-factor on optical transition energy was measured. It is shown that the electron g-factors are similar for quantum dots with very different geometrical parameters, and their change with optical transition energy is almost identical. The g-factor anisotropy was derived from the data measured in a vector rotate magnet system, which allows full 360 degrees spherical rotation of a magnetic field up to 3T. We determine all g-factor tensor components, and found nearly isotropic electron g-factor and a strong anisotropic hole g-factor.