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Quantifying the intrinsic randomness of quantum measurements| title | Quantifying the intrinsic randomness of quantum measurements |
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| start_date | 2024/01/09 |
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| schedule | 11h |
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| online | no |
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| location_info | Salle 3052 |
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| summary | In this talk, I will tell you about our recent results on the maximum probability with which an adversary, Eve, can guess the outcomes of a known POVM M on a system S in a known state ρ. We study two alternative adversarial scenarios for this problem: a classical one and a quantum one. In the classical picture, every time the system is measured, Eve knows in which pure state from an ensemble compatible with ρ the system is and which extremal POVM in some convex decomposition of M is being performed. In the quantum picture, following [Frauchiger et al., arXiv:1311.4547], the POVM M is seen as a projective measurement on the system S plus an ancillary system A, which can be in a mixed state, and Eve holds a purification E of SA. Notice that these two scenarios are indistinguishable for someone doing tomography on S. We show that, unlike the case of projective measurements (as it was already known) or pure states (as we prove), when nonextremal measurements and states are considered, Eve’s guessing probability in the quantum picture can be strictly greater than in the classical one. |
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| responsibles | Hamoudi |
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Workflow history| from state (1) | to state | comment | date |
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| submitted | published | | 2023/12/19 15:18 UTC |
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