Certifying quantumness beyond steering and nonlocality and its implications on quantum information processing

TL;DR

This paper introduces methods to certify superunsteerability and superlocality, two types of quantum correlations, and explores their implications for quantum randomness certification and quantum information processing.

Contribution

It defines measurable quantities to certify superunsteerability and superlocality, linking them to randomness generation and quantum information tasks, and classifies separable states based on quantumness.

Findings

Certification bounds for genuine randomness in steering scenarios

Inequalities to certify superlocality in Bell scenarios

Superlocality as a resource for random-access codes

Abstract

Superunsteerability is a particular kind of spatial quantum correlation that can be observed in a steering scenario in the presence of limited shared randomness. In this work, we define an experimentally measurable quantity in a steering scenario to certify superunsteerability. In the context of certification of randomness with this scenario, we demonstrate that such certification of superunsteerability provides a bound on the amount of genuine randomness generation. On the other hand, superlocality is another kind of spatial quantum correlation that can be observed in a Bell scenario in the presence of limited shared randomness. We identify inequalities to certify superlocality in the Bell scenarios that can be adopted to implement $2$-to-$1$ and $3$-to-$1$ random-access codes. We observe that such certification of superlocality acts as resource for the random-access codes in the presence of limited shared randomness. As a by-product of our certification of superunsteerability and superlocality, we identify a new classification of separable states having quantumness.