Measurement disturbance and conservation laws in quantum mechanics
Peer reviewed, Journal article
Published version
Permanent lenke
https://hdl.handle.net/11250/3125536Utgivelsesdato
2023Metadata
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Originalversjon
Mohammady, M. H., Miyadera, T., & Loveridge, L. (2023). Measurement disturbance and conservation laws in quantum mechanics. Quantum, 7, Artikkel 1033. https://doi.org/10.22331/q-2023-06-05-1033Sammendrag
Measurement error and disturbance, in the presence of conservation laws, are analysed in general operational terms. We provide novel quantitative bounds demonstrating necessary conditions under which accurate or non-disturbing measurements can be achieved, highlighting an interesting interplay between incompatibility, unsharpness, and coherence. From here we obtain a substantial generalisation of the Wigner-Araki-Yanase (WAY) theorem. Our findings are further refined through the analysis of the fixed-point set of the measurement channel, some extra structure of which is characterised here for the first time.