System information propagation for composite structures

作者：Mironowicz P^*; Nalezyty P; Horodecki P^*; Korbicz J K

来源：PHYSICAL REVIEW A, 2018, 98(2): 022124.

DOI：10.1103/PhysRevA.98.022124

We study in detail the decoherence process of a quantum register, coupled to a composite environment. We use recently developed methods of information transfer study in open quantum systems to analyze information flow between the register and its environment. We show that there are regimes when not only the register decoheres effectively to a classical bit string, but this bit string is redundantly encoded in the environment, making it available to multiple observers. This process is more subtle and in general qualitatively different than in the case of a single qubit due to the presence of various protected subspaces: decoherence-free subspaces and so-called orthogonalization-free subspaces. We show that this leads to a rich structure of coherence loss or protection in the asymptotic state of the register and a part of its environment. We formulate a series of examples illustrating these structures.

• 出版日期2018-8-20