On the optimal measurement for quantum discord of two-qubit states
Quantum Physics
2015-06-03 v1
Abstract
We present an efficient method to solve the quantum discord of two-qubit X states exactly. A geometric picture is used to clarify whether and when the general POVM measurement is superior to von Neumann measurement. We show that either the von Neumann measurement or the three-element POVM measurement is optimal, and more interestingly, in the latter case the components of the postmeasurement ensemble are invariant for a class of states.
Keywords
Cite
@article{arxiv.1110.6681,
title = {On the optimal measurement for quantum discord of two-qubit states},
author = {Mingjun Shi and Chunxiao Sun and Fengjian Jiang and Xinhu Yan and Jiangfeng Du},
journal= {arXiv preprint arXiv:1110.6681},
year = {2015}
}
Comments
6 pages, 4 figures