Biexciton state preparation in a quantum dot via adiabatic rapid   passage: comparison between two control protocols and impact of   phonon-induced dephasing
  We investigate theoretically under which conditions a stable and high-fidelity preparation of the biexciton state in a quantum dot can be realized by means of adiabatic rapid passage in the presence of acoustic phonon coupling. Our analysis is based on a numerically complete real-time path integral approach and comprises different schemes of optical driving using frequency-swept (chirped) pulses. We show that depending on the size of the biexciton binding energy, resonant two-photon excitations or two-color schemes can be favorable. It is demonstrated that the carrier-phonon interaction strongly affects the efficiency of the protocols and that a robust preparation of the biexciton is restricted to positive chirps and low temperatures. A considerable increase of the biexciton yield can be achieved realizing temperatures below 4 K. 
M. Gl\"assl, A. Barth, K. Gawarecki, P. Machnikowski, M. D. Croitoru,   S. L\"uker, D. E. Reiter, T. Kuhn, and V. M. Axt
cond-mat.mes-hall