1209.2675 (K. Gawarecki et al.)

Dephasing in the adiabatic rapid passage in quantum dots: the role of
phonon-assisted biexciton generation    [PDF]

K. Gawarecki, S. Lüker, D. E. Reiter, T. Kuhn, M. Glässl, V. M. Axt, A. Grodecka-Grad, P. Machnikowski

We study the evolution of an exciton confined in a quantum dot adiabatically controlled by a frequency-swept (chirped) laser pulse in the presence of carrier-phonon coupling. We focus on the dynamics induced by a linearly polarized beam and analyze the decoherence due to phonon-assisted biexciton generation. We show that if the biexciton state is shifted down by a few meV, as is typically the case, the resulting decoherence is strong even at low temperatures. As a result, efficient state preparation is restricted to a small parameter area corresponding to low temperatures, positive chirps and moderate pulse areas.

View original: http://arxiv.org/abs/1209.2675