No-relationship between impossibility of faster-than-light quantum communication and distinction of ensembles with the same density matrix
Quantum Physics
2015-06-26 v2
Abstract
It has been claimed in the literature that impossibility of faster-than-light quantum communication has an origin of indistinguishability of ensembles with the same density matrix. We show that the two concepts are not related. We argue that: 1) even with an ideal single-atom-precision measurement, it is generally impossible to produce two ensembles with exactly the same density matrix; or 2) to produce ensembles with the same density matrix, classical communication is necessary. Hence the impossibility of faster-than-light communication does not imply the indistinguishability of ensembles with the same density matrix.
Keywords
Cite
@article{arxiv.quant-ph/0506047,
title = {No-relationship between impossibility of faster-than-light quantum communication and distinction of ensembles with the same density matrix},
author = {Chuan Wang and Gui Lu Long and Yang Sun},
journal= {arXiv preprint arXiv:quant-ph/0506047},
year = {2015}
}
Comments
4 pages and 3 figures