New strategy for suppressing decoherence in quantum computation

Abstract

Controlable strong interaction of the qubit's bath with an external system (i.e. with the bath's environment) allows for choosing the conditions under which the decoherence of the qubit's states can be substantially decreased (in a certain limit: completely avoided). By "substantially decreased" we mean that the correlations which involve the bath's states prove negligible, while the correlations between the qubit's and the environment's states can be made ineffective during a comparatively long time interval. So, effectively, one may choose the conditions under which, for sufficiently long time interval, the initial state of "qubit + bath" remains unchanged, thus removing any kind of the errors. The method has been successfully employed in the (simplified) model of the solid-state-nuclear quantum computer (proposed by Kane).