Non-Gaussian Dissipative Quantum Thermometry Beyond Gaussian Bounds

TL;DR

This paper establishes analytic bounds on quantum Fisher information for temperature estimation in open quantum systems, revealing that non-Gaussian states like Fock states can outperform Gaussian probes in dissipative environments.

Contribution

It provides the first analytic bounds on non-Gaussian quantum thermometry, highlighting the advantage of Fock states over Gaussian states in dissipative regimes.

Findings

Fock states exhibit linear-in-time QFI scaling, outperforming Gaussian quadratic scaling.

Analytic bounds clarify when non-Gaussian resources provide a thermometric advantage.

Numerical simulations confirm theoretical predictions and suggest experimental feasibility.

Abstract

The fundamental metrological limits of temperature sensing in open quantum systems remain largely unresolved, particularly regarding the role of non-Gaussian quantum resources. In this letter, we establish analytic bounds on the quantum Fisher information (QFI) for temperature estimation using non-Gaussian states undergoing dissipative bosonic evolution. By focusing on the short-time regime governed by a time-local master equation, we derive precise scaling laws that elucidate when and how non-Gaussian probes decisively outperform Gaussian states under identical energy constraints. Our analysis uncovers a distinct linear-in-time QFI enhancement unique to Fock states, in contrast to the inherently weaker, quadratic scaling of Gaussian probes. These theoretical insights are substantiated through exact numerical simulations and mapped onto experimentally accessible platforms such as circuit QED. Our results not only clarify the quantum thermometric advantage of non-Gaussianity but also chart a realistic pathway toward harnessing it in noisy quantum technologies.