On the edge of the set of no-signaling assemblages
Abstract
Following recent advancements, we consider a scenario of multipartite postquantum steering and general no-signaling assemblages. We introduce the notion of the edge of the set of no-signaling assemblages and we present its characterization. Next, we use this concept to construct witnesses for no-signaling assemblages without an LHS model. Finally, in the simplest nontrivial case of steering with two untrusted subsystems, we discuss the possibility of quantum realization of assemblages on the edge. In particular, for three-qubit states, we obtain a no-go type result, which states that it is impossible to produce assemblage on the edge using measurements described by POVMs as long as the rank of a given state is greater than or equal to 3.
Keywords
Cite
@article{arxiv.2008.12325,
title = {On the edge of the set of no-signaling assemblages},
author = {Michał Banacki and Ricard Ravell Rodríguez and Paweł Horodecki},
journal= {arXiv preprint arXiv:2008.12325},
year = {2021}
}
Comments
We extended the proof of the main theorem, made some changes in the writing and changed the title