Quantum optical properties of a singleInxGa1−xAs−GaAsquantum dot two-level system

Abstract

We report on a two-level system, defined by the ground-state exciton of a single $\mathrm{In}\mathrm{Ga}\mathrm{As}∕\mathrm{Ga}\mathrm{As}$ quantum dot. Saturation spectroscopy combined with ultrahigh spectral resolution gives us a complete description of the system in the steady-state limit. Rabi oscillations and quantum interference experiments, on the other hand, provide a detailed insight into the coherent high excitation regime. All fundamental properties of the two-level system show an excellent quantitative agreement in both domains, even though obtained under entirely different experimental conditions. We thus are able to demonstrate control over an almost ideal two-level system, suitable for possible applications in quantum information processing.