Genuine High-Order Einstein-Podolsky-Rosen Steering

TL;DR

This paper introduces a new formalism for genuine high-order EPR steering in multipartite quantum systems, experimentally demonstrating four-partite steering and its applications to one-way quantum computing.

Contribution

It develops a novel formalism to explore high-order EPR steering in complex multipartite quantum systems, enabling efficient experimental certification.

Findings

First experimental demonstration of genuine four-partite EPR steering.

Application of EPR steering to universal one-way quantum computing.

Efficient certification with few measurement settings.

Abstract

Einstein-Podolsky-Rosen (EPR) steering demonstrates that two parties share entanglement even if the measurement devices of one party are untrusted. Here, going beyond this bipartite concept, we develop a novel formalism to explore a large class of EPR steering from generic multipartite quantum systems of arbitrarily high dimensionality and degrees of freedom, such as graph states and hyperentangled systems. All of these quantum characteristics of genuine high-order EPR steering can be efficiently certified with few measurement settings in experiments. We faithfully demonstrate for the first time such generality by experimentally showing genuine four-partite EPR steering and applications to universal one-way quantum computing. Our formalism provides a new insight into the intermediate type of genuine multipartite Bell non-locality and potential applications to quantum of untrusted measurement devices.