Rotational invariance and spin measurements

✍ Scribed by G.C. Ghirardi; A. Rimini; T. Weber

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 240 KB
• Volume: 114
• Category: Article
• ISSN: 0378-4371
• DOI: 10.1016/0378-4371(82)90291-6

✦ Synopsis

The existence of additive conserved quantities implies, as is well known, unavoidable deviations from the ideal von Neumann scheme in the measurement of those observables which do not commute with the conserved quantities. We introduce a formal procedure which allows the derivation of a lower bound for the total squared norm of the non-ideal terms in the case of a measurement of a spin component for a quantum system of arbitrary spin.