Spatio-Temporal Steering for Testing Nonclassical Correlations in Quantum Networks

TL;DR

This paper introduces spatio-temporal steering (STS), a new framework to evaluate nonclassical correlations in quantum networks, with applications in quantum transport and biological systems, exemplified by photosynthetic complexes.

Contribution

The paper defines STS, proposes measures for it, and demonstrates its application in assessing quantum correlations in complex biological and nano-structured systems.

Findings

STS measures enable assessment of nonclassical correlations.

Application to photosynthetic complexes shows quantum effects.

STS generalizes existing steering concepts.

Abstract

We introduce the concept of spatio-temporal steering (STS), which reduces, in special cases, to Einstein-Podolsky-Rosen steering and the recently-introduced temporal steering. We describe two measures of this effect referred to as the STS weight and robustness. We suggest that these STS measures enable a new way to assess nonclassical correlations in an open quantum network, such as quantum transport through nano-structures or excitation transfer in a complex biological system. As one of our examples, we apply STS to check nonclassical correlations among sites in a photosynthetic pigment-protein complex in the Fenna-Matthews-Olson model.