Abstract
We study finite-time Landau-Zener transitions at a singlet-triplet level crossing in a GaAs double quantum dot, both experimentally and theoretically. Sweeps across the anticrossing in the high driving speed limit result in oscillations with a small visibility. Here we demonstrate how to increase the oscillation visibility while keeping sweep times shorter than using a tailored pulse with a detuning dependent level velocity. Our results show an improvement of a factor of for the oscillation visibility. In particular, we were able to obtain a visibility of for Stückelberg oscillations, which demonstrates the creation of an equally weighted superposition of the qubit states.
- Received 12 July 2012
DOI:https://doi.org/10.1103/PhysRevLett.110.086804
© 2013 American Physical Society