Rozonoèr, L. I. Determination of a state of a quantum system from results of measurements. (English. Russian original) Zbl 0967.81004 Probl. Inf. Transm. 35, No. 4, 359-368 (1999); translation from Probl. Peredachi Inf. 35, No. 4, 84-94 (1999). Summary: It is shown that for determining a pure state of a quantum system (in a finite- or infinite-dimensional case), it suffices to measure four certain observables, and any two of them are not sufficient. Another problem considered is the determination of a mixed state in the finite-dimensional case where the space dimension \(N\) is not a prime number. MSC: 81P15 Quantum measurement theory, state operations, state preparations Keywords:determining a pure state; mixed state PDF BibTeX XML Cite \textit{L. I. Rozonoèr}, Probl. Inf. Transm. 35, No. 4, 359--368 (1999; Zbl 0967.81004); translation from Probl. Peredachi Inf. 35, No. 4, 84--94 (1999)