Control of the non-Markovian dynamics of a qubit

Solid-state implementations of a qubit based on semiconductor quantum dots or Josephson junctions are studied within a driven spin-boson model with Ohmic spectral function. It is shown that direct or indirect optimization allows selection of simple control fields which drive the dissipative system from a given initial state to a selected target state provided that the system's intrinsic minimal response times are respected. The control field can be used to establish interference between the system-bath and system-control interactions, leading to control over effective transition rates and the dissipative action of the environment. (c) 2006 American Institute of Physics.