Quantum Mechanics of Measurement
Abstract
An analysis of quantum measurement is presented that relies on an information-theoretic description of quantum entanglement. In a consistent quantum information theory of entanglement, entropies (uncertainties) conditional on measurement outcomes can be negative, implying that measurement can be described via unitary, entropy-conserving, interactions, while still producing randomness in a measurement device. In such a framework, quantum measurement is not accompanied by a wave-function collapse, or a quantum jump. The theory is applied to the measurement of incompatible variables, giving rise to a stronger entropic uncertainty relation than heretofore known. It is also applied to standard quantum measurement situations such as the Stern-Gerlach and double-slit experiments to illustrate how randomness, inherent in the conventional quantum probabilities, arises in a unitary framework. Finally, the present view clarifies the relationship between classical and quantum concepts.
Cite
@article{arxiv.quant-ph/9605002,
title = {Quantum Mechanics of Measurement},
author = {N. J. Cerf and C. Adami},
journal= {arXiv preprint arXiv:quant-ph/9605002},
year = {2008}
}
Comments
18 pages RevTex incl. 8 figures, submitted to Phys. Rev. A. Revised abstract and introduction. Added discussion on separability and entropic uncertainty relations