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arXiv · 2505.09456

Quantum state-agnostic work extraction (almost) without dissipation

Josep Lumbreras·Ruo Cheng Huang·Yanglin Hu·Mile Gu·Marco Tomamichel
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Abstract

We investigate work extraction protocols designed to transfer the maximum possible energy to a battery using sequential access to $N$ copies of an unknown pure qubit state. The core challenge is designing interactions to optimally balance two competing goals: charging of the battery optimally using the qubit in hand, and acquiring more information by qubit to improve energy harvesting in subsequent rounds. Here, we leverage exploration-exploitation trade-off in reinforcement learning to develop adaptive strategies achieving energy dissipation that scales only poly-logarithmically in $N$. This represents an exponential improvement over current protocols based on full state tomography.

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Josep Lumbreras, Ruo Cheng Huang, Yanglin Hu, Mile Gu, Marco Tomamichel. 2025-05-14. Quantum state-agnostic work extraction (almost) without dissipation. https://arxiv.org/abs/2505.09456

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