Controlled high-fidelity navigation in the charge stability diagram of a double quantum dot

DIEGO S. ACOSTA CODEN; RODOLFO H. ROMERO; ESA RÄSANEN

JOURNAL OF PHYSICS CONDENSED MATTER

IOP PUBLISHING LTD

Lugar: Londres; Año: 2015 vol. 27 p. 115303 - 115303

0953-8984

We propose an efficient control protocol for charge transfer in a double quantum dot. We consider numerically a two-dimensional model system, where the quantum dots are subjected to time-dependent electric fields corresponding to experimental gate voltages. Our protocol enables navigation in the charge stability diagram from a state to another through controllable variation of the fields. We show that the well-known adiabatic Landau?Zener transition?when supplemented with a time-dependent field tailored with optimal control theory?can remarkably improve the transition speed. The results also lead to a simple control scheme obtained from the experimental charge stability diagram that requires only a single parameter. Eventually, we can achieve the ultrafast performance of the composite pulse protocol that allows the system to be driven at the quantum speed limit.