Measuring complete quantum states with a single observable

Journal Article · Mon Oct 15 00:00:00 EDT 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.76.042117· OSTI ID:21020659

Xinhua, Peng; Suter, Dieter ^[1]; Jiangfeng, Du ^[1]

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1. Fachbereich Physik, Universitaet Dortmund, 44221 Dortmund (Germany)

Experimental determination of an unknown quantum state usually requires several incompatible measurements. However, it is also possible to determine the full quantum state from a single, repeated measurement. For this purpose, the quantum system whose state is to be determined is first coupled to a second quantum system (the 'assistant') in such a way that part of the information in the quantum state is transferred to the assistant. The actual measurement is then performed on the enlarged system including the original system and the assistant. We discuss in detail the requirements of this procedure and experimentally implement it on a simple quantum system consisting of nuclear spins.

• OSTI ID: 21020659
• Journal Information: Physical Review. A, Vol. 76, Issue 4; Other Information: DOI: 10.1103/PhysRevA.76.042117; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EIGENFUNCTIONS
EIGENVALUES
HILBERT SPACE
QUANTUM INFORMATION
SPIN