Post-quantum steering is a stronger-than-quantum resource for information processing

TL;DR

This paper demonstrates that post-quantum steering can be a more powerful resource than quantum steering for information processing tasks like remote state preparation, and introduces a new theoretical framework called Witworld.

Contribution

It introduces Witworld, a new compositional probabilistic theory with strong post-quantum features, and shows post-quantum steering's potential in information processing.

Findings

Post-quantum steering enables more effective remote state preparation.

Witworld provides a new framework for exploring post-quantum phenomena.

Post-quantum steering can arise in theories beyond quantum mechanics.

Abstract

We present the first instance where post-quantum steering is a stronger-than-quantum resource for information processing -- remote state preparation. In addition, we show that the phenomenon of post-quantum steering is not just a mere mathematical curiosity allowed by the no-signalling principle, but it may arise within compositional theories beyond quantum theory, hence making its study fundamentally relevant. We show these results by formulating a new compositional general probabilistic theory -- which we call Witworld -- with strong post-quantum features, which proves to be a intuitive and useful tool for exploring steering and its applications beyond the quantum realm.