English

Nonexistence of a universal quantum machine to examine the precision of unknown quantum states

Quantum Physics 2015-05-30 v2

Abstract

In this work, we reveal a new type of impossibility discovered in our recent research which forbids comparing the closeness of multiple unknown quantum states with any non-trivial threshold in a perfect or an unambiguous way. This impossibility is distinct from the existing impossibilities in that it is a "collective" impossibility on multiple quantum states while most other "no-go" theorems concern with only one single state each time, i.e., it is an impossibility on a non-local quantum operation. This novel impossibility may provide a new insight into the nature of quantum mechanics and it implies more limitations on quantum information tasks than the existing "no-go" theorems.

Keywords

Cite

@article{arxiv.1110.4540,
  title  = {Nonexistence of a universal quantum machine to examine the precision of unknown quantum states},
  author = {Shengshi Pang and Shengjun Wu and Zeng-Bing Chen},
  journal= {arXiv preprint arXiv:1110.4540},
  year   = {2015}
}