

Preprint 51/2015
Maximal Holevo quantity based on weak measurements
Yao-Kun Wang, Shao-Ming Fei, Zhi-Xi Wang, Jun-Peng Cao, and Heng Fan
Contact the author: Please use for correspondence this email.
Submission date: 25. Aug. 2015
Pages: 30
published in: Scientific Reports, 5 (2015), art-no. 10727
DOI number (of the published article): 10.1038/srep10727
Bibtex
Download full preprint: PDF (554 kB)
Abstract:
The Holevo bound is a keystone in many applications of quantum information theory.
We propose `` maximal Holevo quantity for weak measurements'' as the generalization of the maximal Holevo quantity
which is defined as the optimal projective measurements. The scenarios that weak measurements is necessary are
that only the weak measurements can be performed because for example the system is macroscopic or
that one intentionally tries to do so such that the disturbance on the measured system
can be controlled for example in quantum key distribution protocols.
We evaluate systematically the maximal Holevo quantity for weak measurements for Bell-diagonal states and
find a series of results. Furthermore, we find that weak measurements can be realized by noise and project measurements.