Beating the limits with initial correlations
Quantum Physics
2017-11-30 v3 Mesoscale and Nanoscale Physics
Abstract
Fast and reliable reset of a qubit is a key prerequisite for any quantum technology. For real world open quantum systems undergoing non-Markovian dynamics, reset implies not only purification, but in particular erasure of initial correlations between qubit and environment. Here, we derive optimal reset protocols using a combination of geometric and numerical control theory. For factorizing initial states, we find a lower limit for the entropy reduction of the qubit as well as a speed limit. The time-optimal solution is determined by the maximum coupling strength. Initial correlations, remarkably, allow for faster reset and smaller errors. Entanglement is not necessary.
Cite
@article{arxiv.1703.04483,
title = {Beating the limits with initial correlations},
author = {Daniel Basilewitsch and Rebecca Schmidt and Dominique Sugny and Sabrina Maniscalco and Christiane P. Koch},
journal= {arXiv preprint arXiv:1703.04483},
year = {2017}
}