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arXiv · 2409.12759

Informational non-equilibrium concentration

Chung-Yun Hsieh·Benjamin Stratton·Hao-Cheng Weng·Valerio Scarani
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Abstract

Informational contributions to thermodynamics can be studied in isolation by considering systems with fully-degenerate Hamiltonians. In this regime, being in non-equilibrium -- termed informational non-equilibrium -- provides thermodynamic resources, such as extractable work, solely from the information content. The usefulness of informational non-equilibrium creates an incentive to obtain more of it, motivating the question of how to concentrate it: can we increase the local informational non-equilibrium of a product state $\rho\otimes\rho$ under a global closed system (unitary) evolution? We fully solve this problem analytically, showing that it is impossible for two-qubits, and it is always possible to find states achieving this in higher dimensions. Specifically for two-qutrits, we find that there is a single unitary achieving optimal concentration for every state, for which we uncover a Mepmba-like effect. We further discuss the notion of bound resources in this framework, initial global correlations' ability to activate concentration, and applications to concentrating purity and intrinsic randomness.

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Chung-Yun Hsieh, Benjamin Stratton, Hao-Cheng Weng, Valerio Scarani. 2024-09-19. Informational non-equilibrium concentration. https://doi.org/10.1103/physreva.111.052423

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