Minimizing back-action through entangled measurements
Abstract
When an observable is measured on an evolving coherent quantum system twice, the first measurement generally alters the statistics of the second one, which is known as measurement back-action. We introduce, and push to its theoretical and experimental limits, a novel method of back-action evasion, whereby entangled collective measurements are performed on several copies of the system. This method is inspired by a similar idea designed for the problem of measuring quantum work [Perarnau-Llobet \textit{et al}., (https://doi.org/10.1103/PhysRevLett.118.070601) Phys. Rev. Lett. \textbf{118}, 070601 (2017)]. By utilizing entanglement as a resource, we show that the back-action can be extremely suppressed compared to all previous schemes. Importantly, the back-action can be eliminated in highly coherent processes.
Cite
@article{arxiv.2011.09100,
title = {Minimizing back-action through entangled measurements},
author = {Kang-Da Wu and Elisa Bäumer and Jun-Feng Tang and Karen V. Hovhannisyan and Martí Perarnau-Llobet and Guo-Yong Xiang and Chuan-Feng Li and Guang-Can Guo},
journal= {arXiv preprint arXiv:2011.09100},
year = {2020}
}