English

Measurement disturbance and conservation laws in quantum mechanics

Quantum Physics 2023-06-07 v3

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.

Keywords

Cite

@article{arxiv.2110.11705,
  title  = {Measurement disturbance and conservation laws in quantum mechanics},
  author = {M. Hamed Mohammady and Takayuki Miyadera and Leon Loveridge},
  journal= {arXiv preprint arXiv:2110.11705},
  year   = {2023}
}