Conceptual and formal groundwork for the study of resource dependence relations

TL;DR

This paper develops a formal framework to analyze how different resource theories relate and depend on each other, using monotones and an example involving qubit symmetries to illustrate the concepts.

Contribution

It introduces a formal approach to study resource dependence relations and demonstrates its application with a complete analysis of a qubit symmetry example.

Findings

Complete set of monotones derived for the example resource theories

All resource dependence relations identified and characterized

Relations among resource theories are nuanced even in simple cases

Abstract

A resource theory imposes a preorder over states, with one state being above another if the first can be converted to the second by a free operation, and where the set of free operations defines the notion of resourcefulness under study. In general, the location of a state in the preorder of one resource theory can constrain its location in the preorder of a different resource theory. It follows that there can be nontrivial dependence relations between different notions of resourcefulness. In this article, we lay out the conceptual and formal groundwork for the study of resource dependence relations. In particular, we note that the relations holding among a set of monotones that includes a complete set for each resource theory provides a full characterization of resource dependence relations. As an example, we consider three resource theories concerning the about-face asymmetry properties of a qubit along three mutually orthogonal axes on the Bloch ball, where about-face symmetry refers to a representation of $\mathbb{Z}_2$, consisting of the identity map and a $\pi$ rotation about the given axis. This example is sufficiently simple that we are able to derive a complete set of monotones for each resource theory and to determine all of the relations that hold among these monotones, thereby completely solving the problem of determining resource dependence relations. Nonetheless, we show that even in this simplest of examples, these relations are already quite nuanced.