Loss of quantum-mechanical coherence in a measurement process

Hiromichi Nakazato, Saverio Pascazio

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

A quantum-mechanical measurement process is analyzed in terms of a model Hamiltonian describing the interaction between a quantum system (a particle) and a macroscopic apparatus (a detector), which is assumed to be made up of N two-level elementary constituents (molecules). The description of the molecule locations introduces an effective fluctuating coupling constant, and this provokes a loss of quantum-mechanical coherence in the limit of large N. It is argued that coherence is lost statistically, as a result of the interaction: The collapse of the wave function is indeed obtained when the same experiment is performed many times, as a result of the microscopic differences among macroscopically identical initial states of the detector. In this way, insight is obtained into the mechanism engendering the loss of coherence suffered by a quantum-mechanical system when interacting with a macroscopic apparatus, and the concept of wave-function collapse is replaced by that of a statistically defined dephasing process. No classical behavior of the detection system is postulated and the presence of no external observer is required.

Original languageEnglish
Pages (from-to)4355-4366
Number of pages12
JournalPhysical Review A
Volume45
Issue number7
DOIs
Publication statusPublished - 1992
Externally publishedYes

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wave functions
mechanical measurement
detectors
molecules
interactions

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Physics and Astronomy(all)

Cite this

Loss of quantum-mechanical coherence in a measurement process. / Nakazato, Hiromichi; Pascazio, Saverio.

In: Physical Review A, Vol. 45, No. 7, 1992, p. 4355-4366.

Research output: Contribution to journalArticle

Nakazato, Hiromichi ; Pascazio, Saverio. / Loss of quantum-mechanical coherence in a measurement process. In: Physical Review A. 1992 ; Vol. 45, No. 7. pp. 4355-4366.
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