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Entropic measures of indefinite causality in quantum theory
Entropic measures of indefinite causality in quantum theory

Spécialité

Physique théorique, mécanique quantique

Niveau d'étude

Bac+5

Formation

Master 2

Unité d'accueil

Candidature avant le

01/09/2022

Durée

6 mois

Poursuite possible en thèse

oui

Contact

Grinbaum Alexei
+33 1 69 08 12 17

Résumé/Summary
Quantum advantages in quantum protocols arise from the use of superposition or entanglement. The discipline of quantum information has recently come to realize that quantum advantages can also be obtained via another fundamental physical principle: causality.
Quantum advantages in quantum protocols arise from the use of superposition or entanglement. The discipline of quantum information has recently come to realize that quantum advantages can also be obtained via another fundamental physical principle: causality.
Sujet détaillé/Full description
Indefinite causal orders – a non-classical resource based on the indefinite nature of causal relations between operations in Hilbert space – provide a quantum advantage demonstrably different from that of superposition. Recent theoretical and experimental work has shown that causal indefiniteness – a new and experimentally relevant resource for quantum information processing tasks – can be characterized by a violation of a “causal inequality” analogous to the Bell inequality for quantum entanglement. We will study the entropic version of the causal inequality in analogy with the work of Fritz and Chaves on the entropic CHSH inequality. In particular, we will try to understand whether, contrary to a conjecture made in the literature, non-maximally causally indefinite quantum processes can violate an entropic inequality in the bipartite scenario.
Indefinite causal orders – a non-classical resource based on the indefinite nature of causal relations between operations in Hilbert space – provide a quantum advantage demonstrably different from that of superposition. Recent theoretical and experimental work has shown that causal indefiniteness – a new and experimentally relevant resource for quantum information processing tasks – can be characterized by a violation of a “causal inequality” analogous to the Bell inequality for quantum entanglement. We will study the entropic version of the causal inequality in analogy with the work of Fritz and Chaves on the entropic CHSH inequality. In particular, we will try to understand whether, contrary to a conjecture made in the literature, non-maximally causally indefinite quantum processes can violate an entropic inequality in the bipartite scenario.
Mots clés/Keywords
Quantum information
Quantum information
Compétences/Skills
Stage théorique. Discussions et collaboration avec les équipes à l’Institut Néel (Grenoble).

 

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