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arXiv · 2310.12699

Estimation of high-dimensional unitary transformations saturating the Quantum Cram\'er-Rao bound

J. Escandón-Monardes·D. Uzcátegui·M. Rivera-Tapia·S. P. Walborn·A. Delgado
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Abstract

We propose an estimation procedure for $d$-dimensional unitary transformations. For $d>2$, the unitary transformations close to the identity are estimated saturating the quantum Cram\'er-Rao bound. For $d=2$, the estimation of all unitary transformations is also optimal with some prior information. We show through numerical simulations that, even in the absence of prior information, two-dimensional unitary transformations can be estimated with greater precision than by means of standard quantum process tomography.

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J. Escandón-Monardes, D. Uzcátegui, M. Rivera-Tapia, S. P. Walborn, A. Delgado. 2023-10-19. Estimation of high-dimensional unitary transformations saturating the Quantum Cram\'er-Rao bound. https://doi.org/10.22331/q-2024-07-10-1405

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