Information revival without backflow: non-causal explanations for non-Markovian quantum stochastic processes
| Autor: | Buscemi, Francesco, Gangwar, Rajeev, Goswami, Kaumudibikash, Badhani, Himanshu, Pandit, Tanmoy, Mohan, Brij, Das, Siddhartha, Bera, Manabendra Nath |
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| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | The study of information revivals, witnessing the violation of certain data-processing inequalities, has provided an important paradigm in the study of non-Markovian quantum stochastic processes. Although often used interchangeably, we argue here that the notions of "revivals" and "backflows", i.e., flows of information from the environment back into the system, are distinct: an information revival can occur without any backflow ever taking place. In this paper, we examine in detail the phenomenon of non-causal revivals and relate them to the theory of short Markov chains and squashed non-Markovianity. We also provide an operational condition, in terms of system-only degrees of freedom, to witness the presence of genuine backflow that cannot be explained by non-causal revivals. As a byproduct, we demonstrate that focusing on processes with genuine backflows, while excluding those with only non-causal revivals, resolves the issue of non-convexity of Markovianity, thus enabling the construction of a convex resource theory of genuine quantum non-Markovianity. Comment: v2: Extended discussion with new results, 9 pages |
| Databáze: | arXiv |
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