Superactivation of memory effects in a classical Markov environment

Fuente: arXiv
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Main Authors: Benatti, Fabio, Nichele, Giovanni
Format: Preprint
Published: 2024
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author Benatti, Fabio
Nichele, Giovanni
author_facet Benatti, Fabio
Nichele, Giovanni
contents We investigate a phenomenon known as Superactivation of Backflow of Information (SBFI); namely, the fact that the tensor product of a non-Markovian dynamics with itself exhibits Backflow of Information (BFI) from environment to system even if the single dynamics does not. Such an effect is witnessed by the non-monotonic behaviour of the Helstrom norm and emerges in the open dynamics of two independent, but statistically coupled, parties. We physically interpret SBFI by means of the discrete-time non-Markovian dynamics of two open qubits collisionally coupled to an environment described by a classical Markov chain. In such a scenario SBFI can be ascribed to the decrease of the qubit-qubit-environment correlations in favour of those of the two qubits, only. We further prove that the same mechanism at the roots of SBFI also holds in a suitable continuous-time limit. We also show that SBFI does not require entanglement to be witnessed, but only the quantumness of the Helstrom ensemble.
format Preprint
id arxiv_https___arxiv_org_abs_2411_17396
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Superactivation of memory effects in a classical Markov environment
Benatti, Fabio
Nichele, Giovanni
Quantum Physics
We investigate a phenomenon known as Superactivation of Backflow of Information (SBFI); namely, the fact that the tensor product of a non-Markovian dynamics with itself exhibits Backflow of Information (BFI) from environment to system even if the single dynamics does not. Such an effect is witnessed by the non-monotonic behaviour of the Helstrom norm and emerges in the open dynamics of two independent, but statistically coupled, parties. We physically interpret SBFI by means of the discrete-time non-Markovian dynamics of two open qubits collisionally coupled to an environment described by a classical Markov chain. In such a scenario SBFI can be ascribed to the decrease of the qubit-qubit-environment correlations in favour of those of the two qubits, only. We further prove that the same mechanism at the roots of SBFI also holds in a suitable continuous-time limit. We also show that SBFI does not require entanglement to be witnessed, but only the quantumness of the Helstrom ensemble.
title Superactivation of memory effects in a classical Markov environment
topic Quantum Physics
url https://arxiv.org/abs/2411.17396