Cloning and joint measurements of incompatible components of spin

Journal Article · Thu Jun 15 00:00:00 EDT 2006 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.73.0· OSTI ID:20787465

Brougham, Thomas; Andersson, Erika; Barnett, Stephen M ^[1]

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1. SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

A joint measurement of two observables is a simultaneous measurement of both quantities upon the same quantum system. When two quantum-mechanical observables do not commute, then a joint measurement of these observables cannot be accomplished directly by projective measurements alone. In this paper we shall discuss the use of quantum cloning to perform a joint measurement of two components of spin associated with a qubit system. We introduce cloning schemes which are optimal with respect to this task. The cloning schemes may be thought to work by cloning two components of spin onto their outputs. We compare the proposed cloning machines to existing cloners.

• OSTI ID: 20787465
• Journal Information: Physical Review. A, Vol. 73, Issue 6; Other Information: DOI: 10.1103/PhysRevA.73.062319; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
COMPARATIVE EVALUATIONS
ENERGY LEVELS
INFORMATION THEORY
QUANTUM COMPUTERS
QUANTUM MECHANICS
QUBITS
SPIN