English

Indistinguishability and improper mixtures

Quantum Physics 2007-05-23 v2

Abstract

All quantum mixtures are what d'Espagnat has termed "improper." His "proper" mixture cannot be created -- if welcher weg, or distinguishing, information exists, an improper mixture results, while in the absence of such information, the resulting "mixture" is a pure state. D'Espagnat has claimed that an interpretation of the improper mixture in terms of subensembles leads to logical inconsistency; this claim is shown to be incorrect, as d'Espagnat's argument fails to account for the indistinguishability of the pure-state subensembles.

Cite

@article{arxiv.quant-ph/0109146,
  title  = {Indistinguishability and improper mixtures},
  author = {K. A. Kirkpatrick},
  journal= {arXiv preprint arXiv:quant-ph/0109146},
  year   = {2007}
}

Comments

4 pages. v2: Improved introduction and presentation of theorem of section 5; other small corrections; theorem nicknames changed