Entanglement preserving maps and the universality of finite time disentanglement (original) (raw)

In this paper we investigate how common is the phenomenon of Finite Time Disentanglement (FTD) with respect to the set of quantum dynamics of bipartite quantum states with finite dimensional Hilbert spaces. Considering a quantum dynamics from a general sense, as just a continuous family of Completely Positive Trace Preserving maps (parametrized by the time variable) acting on the space of the bipartite systems, we conjecture that FTD does not happen only when all maps of the family are induced by local unitary operations. We prove that is the case for dynamics where all maps are induced by unitaries and, for pairs of qubits, where all maps are unital. Moreover, we prove some results about unitaries/CPTP maps preserving product/pure states.