Highly efficient biexciton preparation for quantum-dot entangled photon generation

Abstract

A pulsed laser scenario, designed to prepare a variety of self-assembled quantum dots with nearly 100% population in a biexciton state, is proposed. We use realistic parameters for typical self-assembled quantum dots and show that two-colour sequential as well as concurrent excitation of the biexciton state can virtually eliminate unwanted exciton population and prepare a quantum dot in the biexciton state with near-deterministic accuracy. The ensuing radiative emission would be a prerequisite for a high rate, on-demand, source of entangled photons.