Markovian evolution of quantum coherence under symmetric dynamics

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Lostaglio, Matteo; Korzekwa, Kamil and Milne, Antony. 2017. Markovian evolution of quantum coherence under symmetric dynamics. Physical Review A, 96(3), 032109. ISSN 2469-9926 [Article]

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Official URL: https://journals.aps.org/pra/abstract/10.1103/Phys...

Abstract or Description

Both conservation laws and practical restrictions impose symmetry constraints on the dynamics of open quantum systems. In the case of time-translation symmetry, which arises naturally in many physically relevant scenarios, the quantum coherence between energy eigenstates becomes a valuable resource for quantum information processing. In this work we identify the minimum amount of decoherence compatible with this symmetry for a given population dynamics. This yields a generalisation to higher-dimensional systems of the relation T2 2T1 for qubit decoherence and relaxation times. It also enables us to witness and assess the role of non-Markovianity as a resource for coherence preservation and transfer. Moreover, we discuss the relationship between ergodicity and the ability of Markovian dynamics to indenitely sustain a superposition of diferent energy states. Finally, we establish a formal connection between the resource-theoretic and the master equation approaches to thermodynamics, with the former being a non-Markovian generalisation of the latter. Our work thus brings the abstract study of quantum coherence as a resource towards the realm of actual physical applications.

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Article

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https://doi.org/10.1103/PhysRevA.96.032109