Instrument-based quantum resources: quantification, hierarchies and towards constructing resource theories

Abstract:Quantum resources are certain features of the quantum world that provide advantages in certain information-theoretic, thermodynamic, or other useful operational tasks that are outside the realm of what classical theories can achieve. Quantum resource theories provide us with an elegant framework for studying these resources quantitatively and rigorously. While numerous state-based quantum resource theories have already been investigated, and to some extent, measurement-based resource theories have also been explored, instrument-based resource theories remain largely unexplored, with only a few notable exceptions. As quantum instruments are devices that provide both the classical outcomes of induced measurements and the post-measurement quantum states, they are quite important, especially for scenarios where multiple parties sequentially act on a quantum system. In this work, we study several instrument-based resource theories, namely (1) the resource theory of information preservability, (2) the resource theory of (strong) entanglement preservability, (3) the resource theory of (strong) incompatibility preservability, (4) the resource theory of traditional incompatibility, and (5) the resource theory of parallel incompatibility. Furthermore, we outline the hierarchies of these instrument-based resources and provide measures to quantify them. We then also established a relationship between our resource measure and the advantage in an information-theoretic task. In short, we provide a detailed framework for a wide variety of instrument-based quantum resource theories.

arXiv:2508.09134 [quant-ph]

(or arXiv:2508.09134v3 [quant-ph] for this version)

From: Jatin Ghai Mr. [view email] [v1] Tue, 12 Aug 2025 17:58:30 UTC (249 KB) [v2] Thu, 23 Oct 2025 17:47:07 UTC (373 KB) [v3] Mon, 15 Jun 2026 17:35:50 UTC (375 KB)