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Von Neumann's Entropy Does Not Correspond to Thermodynamic Entropy

Published online by Cambridge University Press:  01 January 2022

Meir Hemmo  and
Orly Shenker
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Abstract

Von Neumann argued by means of a thought experiment involving measurements of spin observables that the quantum mechanical quantity$S_{VN}=-k\mathrm{Tr}\,(\rho \mathrm{log}\,\rho) $ is conceptually equivalent to thermodynamic entropy. We analyze Von Neumann's thought experiment and show that his argument fails.

Type
Research Article
Information
Philosophy of Science , Volume 73 , Issue 2 , April 2006 , pp. 153 - 174
Copyright
Copyright © The Philosophy of Science Association

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Footnotes

‡

We thank Itamar Pitowsky for discussions and anonymous referees for comments on this paper.

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