A biexciton in a semiconductor quantum dot is a source of polarization-entangled photons with high potential for implementation in scalable systems. Several approaches for nonresonant, resonant, and quasiresonant biexciton preparation exist, but all have their own disadvantages; for instance, low fidelity, timing jitter, incoherence, or sensitivity to experimental parameters. We demonstrate a coherent and robust technique to generate a biexciton in an InGaAs quantum dot with a fidelity close to 1. The main concept is the application of rapid adiabatic passage to the ground-state–exciton–biexciton system. We reinforce our experimental results with simulations which include a microscopic coupling to phonons.

• Received 2 December 2016

DOI:https://doi.org/10.1103/PhysRevB.95.161302