Symmetry-induced decoherence-free subspaces

Preservation of coherence is a fundamental yet subtle phenomenon in open systems. We uncover its relation to symmetries respected by the system Hamiltonian and coupling environment. discriminate between local global classes decoherence-free subspaces for many-body systems through introduction "ghost variables". The latter are orthogonal symmetry environment does not depend on them. Constructing them facilitated classical phase space can be transferred quantum mechanics equivalent role that Poisson Lie algebras play mechanics, respectively. Examples given an interacting spin system.