Undoing a quantum measurement
Quantum Physics
2015-06-12 v1
Abstract
In general, a quantum measurement yields an undetermined answer and alters the system to be consistent with the measurement result. This process maps multiple initial states into a single state and thus cannot be reversed. This has important implications in quantum information processing, where errors can be interpreted as measurements. Therefore, it seems that it is impossible to correct errors in a quantum information processor, but protocols exist that are capable of eliminating them if they affect only part of the system. In this work we present the deterministic reversal of a fully projective measurement on a single particle, enabled by a quantum error-correction protocol that distributes the information over three particles.
Cite
@article{arxiv.1211.1791,
title = {Undoing a quantum measurement},
author = {Philipp Schindler and Thomas Monz and Daniel Nigg and Julio T. Barreiro and Esteban A. Martinez and Matthias F. Brandl and Michael Chwalla and Markus Hennrich and Rainer Blatt},
journal= {arXiv preprint arXiv:1211.1791},
year = {2015}
}