Control of decoherence and correlation in single quantum dissipative oscillator systems

A single quantum dissipative oscillator described by the Lindblad equation serves as a model for a nanosystem. This model is solved exactly by using t he ambiguity function. The solution shows the features of decoherence (spat ial extent of quantum behavior), correlation (spatial scale over which the system localizes to its physical dimensions), and mixing (mixed- state spat ial correlation). A new relation between these length scales is obtained he re. By varying the parameters contained in the Lindblad equation, it is sho wn that decoherence and correlation can be controlled. We indicate possible interpretation of the Lindblad parameters in the context of experiments us ing engineered reservoirs. (C) 2001 Elsevier Science B.V. All rights reserv ed.