Multiparticle decoherence-free subspaces in extended systems

Abstract

We develop a method to determine spatial configurations to realize decoherence-free subspaces for spatially extended multiparticle systems. We have assumed normal reservoir behavior including translational invariance of the reservoir and preparation in stationary states or mixture thereof and weak Markovian system-reservoir coupling that requires energy transfer. One important outcome of our method is a proof that there does not exist a multiparticle decoherence-free subspace in such systems except in the limit that the spatial extent of the system becomes infinitesimal.