Postquantum steering

Abstract

The discovery of postquantum nonlocality, i.e., the existence of nonlocal correlations that are stronger than any quantum correlations but nevertheless consistent with the no-signaling principle, has deepened our understanding of the foundations of quantum theory. In this work, we investigate whether the phenomenon of Einstein-Podolsky-Rosen steering, a different form of quantum nonlocality, can also be generalized beyond quantum theory. While postquantum steering does not exist in the bipartite case, we prove its existence in the case of three observers. Importantly, we show that postquantum steering is a genuinely new phenomenon, fundamentally different from postquantum nonlocality. Our results provide new insight into the nonlocal correlations of multipartite quantum systems.

9 pages, 1 figure

References in corpus (10)

• Device-independent security of quantum cryptography against collective attacks
• Steering, Entanglement, Nonlocality, and the EPR Paradox
• A convergent hierarchy of semidefinite programs characterizing the set of quantum correlations
• Experimental criteria for steering and the Einstein-Podolsky-Rosen paradox
• Bounding the set of quantum correlations
• Einstein-Podolsky-Rosen steering provides the advantage in entanglement-assisted subchannel discrimination with one-way measurements
• Joint measurability of generalized measurements implies classicality
• Almost quantum correlations
• Detection of entanglement in asymmetric quantum networks and multipartite quantum steering
• Macroscopically local correlations can violate information causality