Theory of two-photon processes in quantum dots: coherent evolution and phonon-induced dephasing

The paper discusses two-photon Rabi oscillations between the ground state of a quantum dot and the biexciton state, as well as two-photon oscillations between the two single-exciton states with different circular or linear polarizations. The effect of phonon-induced decoherence on these processes is described and optimal system properties and optical driving conditions for coherent control are identified. It is shown that proper optimalization allows one to control the biexciton system via two-photon transitions with a high fidelity.