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arXiv · 2201.07080

Classifying the non-time-local and entangling dynamics of an open qubit system

Sean Prudhoe·Sarah Shandera
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Abstract

We study families of dynamical maps generated from interactions with varying degrees of symmetry. For a family of time-independent Hamiltonians, we demonstrate the relationship between symmetry, strong-coupling, perfect entanglers, non-Markovian features, and non-time-locality. We show that by perturbing the initial environment state, effective time-local descriptions can be obtained that are non-singular yet capture essential non-unitary features of the reduced dynamics. We then consider a time-dependent Hamiltonian that changes the degree of symmetry by activating a dormant degree of freedom. In this example we find that the one-qubit reduced dynamics changes dramatically. These results can inform the construction of effective theories of open systems when the larger system dynamics is unknown.

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Sean Prudhoe, Sarah Shandera. 2022-01-18. Classifying the non-time-local and entangling dynamics of an open qubit system. https://doi.org/10.1007/jhep02(2023)007

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