Path summation and von Neumann-like quantum measurements

Journal Article · Fri Apr 01 00:00:00 EST 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.71.042101· OSTI ID:20653248

Sokolovski, D; Sala Mayato, R ^[1]

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1. School of Mathematics and Physics, Queen's University of Belfast, Belfast, BT7 1NN (United Kingdom)

We demonstrate how a general von Neumann-like measurement can be analyzed in terms of histories (paths) constructed for the measured variable A. The Schroedinger state of a system in a Hilbert space of arbitrary dimensionality is decomposed into a set of substates, each of which corresponds to a particular detailed history of the system. The coherence between the substates may then be destroyed by meter(s) to a degree determined by the nature and the accuracy of the measurement(s) which may be of von Neumann, finite-time, or continuous type. The cases of a particle described by Feynman paths in the coordinate space and a qubit in a two-dimensional Hilbert space are studied in some detail.

• OSTI ID: 20653248
• Journal Information: Physical Review. A, Vol. 71, Issue 4; Other Information: DOI: 10.1103/PhysRevA.71.042101; (c) 2005 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
71 CLASSICAL AND QUANTUM MECHANICS
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QUANTUM MECHANICS
QUANTUM NUMBERS
SCHROEDINGER EQUATION
TWO-DIMENSIONAL CALCULATIONS