Spin-flip Raman scattering of the resident electron in singly charged (In,Ga)As/GaAs quantum dot ensembles

Highly efficient spin-flip Raman scattering of the resident electron spin is found in singly charged (In,Ga)As/GaAs quantum dots. The applied magnetic field induces a symmetry reduction for the negatively charged exciton, which serves as intermediate scattering state, thus making the spin-flip Raman scattering of the resident electron allowed. Electron-electron exchange interaction mediates the electron spin-flip. Above a threshold magnetic field that depends on the dot size and experiment geometry, the efficiency of the scattering cross section is spectrally shifted with increasing field. This shift, which follows the electron cyclotron energy, is assigned to a hybridization of s-shell singlet and p-shell triplet states of the negatively charged exciton.