Ultimate Limits of Thermal Pattern Recognition

TL;DR

This paper establishes the fundamental quantum limits for thermal image classification, demonstrating that quantum strategies can significantly outperform classical methods in low-loss thermal imaging scenarios.

Contribution

It derives the ultimate quantum limits for thermal pattern recognition and shows how quantum-enhanced techniques can provide a notable advantage over classical approaches.

Findings

Quantum strategies outperform classical in low-loss regimes.

Quantum resources enable higher precision in thermal image classification.

Numerical results confirm quantum advantage with quantum sensors and machine learning.

Abstract

Quantum Channel Discrimination (QCD) presents a fundamental task in quantum information theory, with critical applications in quantum reading, illumination, data-readout and more. The extension to multiple quantum channel discrimination has seen a recent focus to characterise potential quantum advantage associated with quantum enhanced discriminatory protocols. In this paper, we study thermal imaging as an environment localisation task, in which thermal images are modelled as ensembles of Gaussian phase insensitive channels with identical transmissivity, and pixels possess properties according to background (cold) or target (warm) thermal channels. Via the teleportation stretching of adaptive quantum protocols, we derive ultimate limits on the precision of pattern classification of abstract, binary thermal image spaces, and show that quantum enhanced strategies may be used to provide significant quantum advantage over known optimal classical strategies. The environmental conditions and necessary resources for which advantage may be obtained are studied and discussed. We then numerically investigate the use of quantum enhanced statistical classifiers, in which quantum sensors are used in conjunction with machine learning image classification methods. Proving definitive advantage in the low loss regime, this work motivates the use of quantum enhanced sources for short-range thermal imaging and detection techniques for future quantum technologies.