From Quantum Chaos to Classical Chaos via Gain-Induced Measurement Dynamics in a Photon Gas

TL;DR

This paper demonstrates how gain-induced measurement dynamics in a photon gas can lead to the emergence of classical chaos from quantum systems, providing a physical mechanism for the quantum-classical transition.

Contribution

It introduces gain competition as an operational quantum measurement process that naturally produces classical chaos from quantum superpositions.

Findings

Gain competition acts as a measurement selecting motional modes.

Classical chaos emerges from quantum superpositions via gain dynamics.

Quantum measurement features like irreversibility arise from gain processes.

Abstract

How classical chaos emerges from quantum mechanics remains a central open question, as the unitary evolution of isolated quantum systems forbids exponential sensitivity to initial conditions. A key insight is that this quantum-classical link is provided by measurement processes. In this work, we identify gain competition in a chaotic photon gas as an operational quantum measurement that selects single motional modes from an initial superposition through stochastic, nonlinear amplification. We show that this mechanism naturally gives rise to classical chaotic behavior, most notably sensitivity to initial conditions. Our results provide a concrete physical mechanism for the quantum-classical transition in a chaotic system and demonstrate that essential aspects of quantum measurement-state projection, Born-rule-like selection, and irreversibility-can naturally emerge from intrinsic gain dynamics.