### Résumé

langue | Anglais |
---|---|

Numéro d'article | 305302 |

Nombre de pages | 26 |

journal | Journal of Physics A: Mathematical and Theoretical |

Volume | 50 |

Les DOIs | |

état | Publié - 29 juin 2017 |

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**Geometric description of modular and weak values in discrete quantum systems using the Majorana representation.** / Cormann, Mirko; Caudano, Yves.

Résultats de recherche: Recherche - Revue par des pairs › Article

TY - JOUR

T1 - Geometric description of modular and weak values in discrete quantum systems using the Majorana representation

AU - Cormann,Mirko

AU - Caudano,Yves

PY - 2017/6/29

Y1 - 2017/6/29

N2 - We express modular and weak values of observables of three- and higher- level quantum systems in their polar form. The Majorana representation of N-level systems in terms of symmetric states of N−1 qubits provides us with a description on the Bloch sphere. With this geometric approach, we find that modular and weak values of observables of N-level quantum systems can be factored in N−1 contributions. Their modulus is determined by the product of N−1 ratios involving projection probabilities between qubits, while their argument is deduced from a sum of N−1 solid angles on the Bloch sphere. These theoretical results allow us to study the geometric origin of the quantum phase discontinuity around singularities of weak values in three-level systems. We also analyze the three box paradox [1] from the point of view of a bipartite quantum system. In the Majorana representation of this paradox, an observer comes to opposite conclusions about the entanglement state of the particles that were successfully pre-and postselected.

AB - We express modular and weak values of observables of three- and higher- level quantum systems in their polar form. The Majorana representation of N-level systems in terms of symmetric states of N−1 qubits provides us with a description on the Bloch sphere. With this geometric approach, we find that modular and weak values of observables of N-level quantum systems can be factored in N−1 contributions. Their modulus is determined by the product of N−1 ratios involving projection probabilities between qubits, while their argument is deduced from a sum of N−1 solid angles on the Bloch sphere. These theoretical results allow us to study the geometric origin of the quantum phase discontinuity around singularities of weak values in three-level systems. We also analyze the three box paradox [1] from the point of view of a bipartite quantum system. In the Majorana representation of this paradox, an observer comes to opposite conclusions about the entanglement state of the particles that were successfully pre-and postselected.

UR - https://arxiv.org/abs/1612.07023v2

U2 - 10.1088/1751-8121/aa7639

DO - 10.1088/1751-8121/aa7639

M3 - Article

VL - 50

JO - Journal of Physics A: Mathematical and Theoretical

T2 - Journal of Physics A: Mathematical and Theoretical

JF - Journal of Physics A: Mathematical and Theoretical

SN - 1751-8113

M1 - 305302

ER -