Quantum discord as resource for remote state preparation

Author(s): B. Dakić, Y.-O. Lipp, X.-S. Ma, M. Ringbauer, S. Kropatschek, S. Barz, T. Paterek, V. Vedral, A. Zeilinger, Č. Brukner, P. Walther

Journal: Nature Physics

Volume: 8

Page(s): 666-670

Year: 2012

DOI Number: 10.1038/nphys2377

Link: Link to publication

Abstract:

The existence of better-than-classical quantum information processing (QIP) models which consume very little or no entanglement suggests that separable or weakly entangled states could be extremely useful tools for information processing as they are much easier to prepare and control even in dissipative environments. It has been proposed that a resource of advantage is the generation of quantum discord, a measure of non-classical correlations that includes entanglement as a subset. Here we show that quantum discord is the necessary resource for quantum remote state preparation. We explicitly show that the geometric measure of quantum discord is related to the fidelity of this task, which provides its operational meaning. Our results are experimentally demonstrated using photonic quantum systems. Moreover, we demonstrate that separable states with non-zero quantum discord can outperform entangled states. Therefore, the role of quantum discord might provide fundamental insights for resource-efficient QIP.

Note: http://arxiv.org/abs/1203.1629

Zeilinger Group Zeilinger Group , Brukner Group