Magneto-optical studies of self-organized InAs/GaAs quantum dots

Magneto-photoluminescence and photoluminescence excitation (PLE) measurements of self-organized InAs/GaAs quantum dots are reported. For fields applied along the growth direction the first excited-state transition exhibits a linear Zeeman splitting, consistent with a transition between the ground electron state and an excited $p$-like hole state $\left(\Delta n\ne 0\right).$ The hole mass determined from the splitting is in good agreement with the value obtained from a k⋅p calculation for the highly strained dots. The size of the splitting decreases as the field is rotated away from the growth direction, demonstrating the highly anisotropic nature of the carrier wave function. A comparison of spectra recorded at high dot carrier occupancies (≫1) in photoluminescence and at low carrier occupancies (≪1) in PLE reveals the influence of many-carrier Coulomb interactions.