Work

Superactivation of memory effects in a classical Markov environment

Year: 2025

Type: article

Abstract: 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.

Source: Physica Scripta

DOI: 10.1088/1402-4896/add57e

Authors: Fabio Benatti, Giovanni Nichele

Institutions: University of Trieste, Istituto Nazionale di Fisica Nucleare, Sezione di Trieste

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $2,400

Funder: Ministero dell'Università e della Ricerca