Confidence and Backaction in the Quantum Filter Equation
Quantum Physics
2013-03-19 v3 Mesoscale and Nanoscale Physics
Abstract
We study the confidence and backaction of state reconstruction based on a continuous weak measurement and the quantum filter equation. As a physical example we use the traditional model of a double quantum dot being continuously monitored by a quantum point contact. We examine the confidence of the estimate of a state constructed from the measurement record, and the effect of backaction of that measurement on that state. Finally, in the case of general measurements we show that using the relative entropy as a measure of confidence allows us to define the lower bound on the confidence as a type of quantum discord.
Cite
@article{arxiv.1207.3942,
title = {Confidence and Backaction in the Quantum Filter Equation},
author = {Wei Cui and Neill Lambert and Yukihiro Ota and Xin-You Lü and Z. -L. Xiang and J. Q. You and Franco Nori},
journal= {arXiv preprint arXiv:1207.3942},
year = {2013}
}
Comments
9 pages, 6 figures