  We propose a general approach of protecting a two-level system against
decoherence via quantum engineering of non-classical multiple superpositions of
coherent states in a non-Markovian reservoir. The scheme surprisingly only uses
the system-environment interaction responsible for the decoherence and
projective measurements of the two-level system. We demonstrate the method on
the example of an excitonic qubit in self-assembled semiconductor quantum dots
coupled to super-Ohmic reservoir of acoustic phonons.
