Quantum Coherence as a Thermodynamic Resource Beyond the Classical Uncertainty Bound

The precision of nonequilibrium thermodynamic systems is fundamentally limited, yet how quantum coherence shapes these limits remains largely unexplored. A general theoretical framework is introduced that explicitly links quantum coherence to thermodynamic uncertainty relations. By defining a coherence-sensitive measure, it is shown that quantum effects can relax the classical trade-off between the entropy production and the current fluctuations, enabling the precision beyond classical bounds. Application to a three-level quantum maser illustrates the framework in a concrete setting. These results establish quantum coherence as a genuine thermodynamic resource and provide a unified perspective connecting classical and quantum approaches to nonequilibrium thermodynamics.