Instability as a Quantum Resource

TL;DR

This paper introduces instability as a unifying quantum resource theory that encompasses coherence, athermality, and nonuniformity, providing a framework for understanding their interrelations and operational conversions.

Contribution

It formulates instability axiomatically, derives monotones, and establishes a universal second law governing all instability conversions in quantum systems.

Findings

Computed one-shot distillation yield and dilution cost.

Identified extremal additive monotones for instability.

Established a universal second law for quantum instability.

Abstract

We consolidate coherence, athermality, and nonuniformity as sub-resources within an underlying quantum resource theory: instability. We formulate instability axiomatically as the transient information within a decaying physical system. Specifying a decay mechanism (e.g., dephasing, thermalization) recovers these familiar resources as specific manifestations of instability. We compute the one-shot distillation yield and dilution cost in various operational paradigms, and use them to pin down the extremal additive monotones. In the asymptotic regime, we show that all conversion rates are governed by a single additive monotone, and thereby we establish a universal second law for instability.