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Abstract

Nowadays, it is widely acknowledged that information can serve as a thermodynamic fuel capable of powering the extraction of useful work through measurements and feedback control. Moreover, it has been demonstrated that the work extractable from a correlated bipartite state can effectively distinguish entangled states from separable ones. In this context, we introduce an operational criterion denoted as EW to witness the presence of entanglement in a two-mode Gaussian state rho AB, based on the amount of work that can be extracted from a thermal bath using a Szilard-like engine. In this setup, the state rho AB acts as the working medium of the engine, where modes A and B are generated during the first and second transitions of a nondegenerate three-level laser, and are coupled to a shared two-mode thermal bath. Our results reveal that the proposed criterion EW vanishes when rho AB is a product state. Furthermore, EW reaches its maximum value when rho AB is coupled to a vacuum bath, but it diminishes under the influence of thermal noise. Notably, the degree of entanglement detected by EW can be tuned via the atomic coherence of the laser. Finally, a comparison of EW with a reliable measure of entanglement such as logarithmic negativity, demonstrates perfect agreement in identifying the presence of entanglement in rho AB.