Measurement disturbance and conservation laws in quantum mechanics

• URL: http://arxiv.org/abs/2110.11705v3
• Date: Thu, 25 May 2023 17:11:16 GMT
• Title: Measurement disturbance and conservation laws in quantum mechanics
• Authors: M. Hamed Mohammady, Takayuki Miyadera, Leon Loveridge
• Abstract summary: We provide novel quantitative bounds demonstrating necessary conditions under which accurate or non-disturbing measurements can be achieved. We obtain a substantial generalisation of the Wigner-Araki-Yanase (WAY) theorem.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: 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.

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