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arXiv · 2307.08405

Barycentric decomposition for quantum instruments

Juha-Pekka Pellonpää·Erkka Haapasalo·Roope Uola
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Abstract

We present a barycentric decomposition for quantum instruments whose output space is finite-dimensional and input space is separable. As a special case, we obtain a barycentric decomposition for channels between such spaces and for normalized positive-operator-valued measures in separable Hilbert spaces. This extends the known results by Ali and Chiribella et al. on decompositions of quantum measurements, and formalises the fact that every instrument between finite-dimensional Hilbert spaces can be represented using only finite-outcome instruments.

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Juha-Pekka Pellonpää, Erkka Haapasalo, Roope Uola. 2023-07-17. Barycentric decomposition for quantum instruments. https://doi.org/10.1088/1751-8121/ad233c

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