Electron and spin dynamics in a single quantum emitter.

The Auger-Meitner effect is a fundamental electron-electron scattering process that impacts the electron and spin dynamics in semiconductor quantum emitters, such as colloidal nanocrystals and quantum dots. Here, we present an experimental study of the magnetic-field dependence of Auger-Meitner recombination and spin-related scattering processes in a single self-assembled InAs quantum dot. Using two-color, time-resolved resonance fluorescence with spectrally separated detection of both exciton and trion transitions, we extract the Auger-Meitner recombination rate, the electron spin-flip relaxation rate, and the spin-flip Raman scattering rate over a broad magnetic-field range from to . We observe a suppression of the Auger-Meitner recombination rate for magnetic fields above . In contrast, the electron spin-flip relaxation rate increases strongly for fields above and decreases at lower magnetic fields, while the spin-flip Raman scattering rate remains nearly constant. Our results demonstrate that two-color, time-resolved resonance fluorescence enables access to all relevant microscopic rates for optimizing quantum dots as building blocks for future quantum technologies.