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Updated: Feb 24, 2026
07:56
A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
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Ergotropic Characterization of Continuous-Variable Entanglement
Beatriz Polo-Rodríguez1, Federico Centrone1,2, Gerardo Adesso3
1ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Avinguda Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain.
Physical Review Letters
|February 22, 2026
Summary
We introduce a new method using ergotropy, a measure of extractable work, to detect entanglement in quantum systems. This ergotropy-based criterion offers an alternative to entropy measures for understanding quantum correlations in optical platforms.
Area of Science:
- Quantum Physics
- Thermodynamics
- Quantum Information Science
Background:
- Continuous-variable quantum thermodynamics in the Gaussian regime explores quantum correlations in optical systems.
- Ergotropy, the maximum extractable work via unitary operations, is a key thermodynamic quantity.
Purpose of the Study:
- To introduce an entropy-free criterion for entanglement detection in bipartite Gaussian states.
- To establish a direct operational link between entanglement and energy storage.
Main Methods:
- Defining the "relative ergotropic gap" to quantify the disparity between global and local ergotropy.
- Deriving two independent analytical bounds to distinguish entangled from separable states.
- Extending the analysis to certain non-Gaussian states.
Main Results:
- Developed an ergotropy-based criterion for entanglement detection, free from entropy measures.
- Derived bounds that are necessary and sufficient for a broad class of quantum states.
- Observed that Gaussian ergotropy reflects thermodynamic signatures in entangled non-Gaussian states.
Conclusions:
- The ergotropic approach captures different aspects of quantum correlations compared to entropy-based measures.
- This method provides an experimentally accessible approach to entanglement detection in continuous-variable optical platforms.
- Established a direct link between entanglement and energy storage in quantum systems.
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