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Related papers: Sample Complexity of Black Box Work Extraction

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We consider work extraction from $N$ copies of a quantum system. When the same work-extraction process is implemented on each copy, the relative size of fluctuations is expected to decay as $1/\sqrt{N}$. Here, we consider protocols where…

Quantum Physics · Physics 2019-08-15 Martí Perarnau-Llobet , Raam Uzdin

The quantum ergotropy quantifies the maximal amount of work that can be extracted from a quantum state without changing its entropy. Given that the ergotropy can be expressed as the difference of quantum and classical relative entropies of…

Quantum Physics · Physics 2021-08-26 Akira Sone , Sebastian Deffner

Motivated by the recent interest in thermodynamics of micro- and mesoscopic quantum systems we study the maximal amount of work that can be reversibly extracted from a quantum system used to store temporarily energy. Guided by the notion of…

Quantum Physics · Physics 2013-05-01 Robert Alicki , Mark Fannes

Quantum thermodynamic process involves manipulating and controlling quantum states to extract energy or perform computational tasks with high efficiency. There is still no efficientgeneral method to theoretically quantify the effect of the…

Quantum Physics · Physics 2024-06-21 Ming-Xing Luo

Entanglement entropy is one of the most prominent measures in quantum physics. We show that it has an interesting ergotropic interpretation in terms of unitarily extracted work. It determines how much energy one can extract from a source of…

Quantum Physics · Physics 2023-06-16 Dominik Šafránek

Work extraction protocol is always a significant issue in the context of quantum batteries, in which the notion of ergotropy is used to quantify a particular amount of energy that can be extracted through unitary processes. Given the total…

Quantum Physics · Physics 2021-10-04 F. H. Kamin , S. Salimi , Alan C. Santos

The resource-theoretic approach to quantum thermodynamics assumes complete knowledge of the thermal equilibrium against which thermodynamic resources are defined. In practice, however, this state is determined by the system Hamiltonian and…

Quantum Physics · Physics 2026-04-16 Munan Zhang , Kun Fang

Quantum coherence, encoded in the off-diagonal elements of a system's density matrix, is a key resource in quantum thermodynamics, fundamentally limiting the maximum extractable work known as ergotropy. While previous experiments have…

Quantum Physics · Physics 2025-12-04 Li Li , Silu Zhao , Yun-Hao Shi , Kai Xu , Heng Fan , Dongning Zheng , Zhongcheng Xiang

We investigate how the presence of quantum correlations can influence work extraction in closed quantum systems, establishing a new link between the field of quantum non-equilibrium thermodynamics and the one of quantum information theory.…

Quantum Physics · Physics 2017-11-17 Gianluca Francica , John Goold , Mauro Paternostro , Francesco Plastina

A suitable way of quantifying work for microscopic quantum systems has been constantly debated in the field of quantum thermodynamics. One natural approach is to measure the average increase in energy of an ancillary system, called the…

Quantum Physics · Physics 2018-05-16 Nelly Huei Ying Ng , Mischa Woods , Stephanie Wehner

We propose a new form of the Second Law inequality that defines a tight bound for extractable work from the non-equilibrium quantum state. In classical thermodynamics, the optimal work is given by the difference of free energy, what…

Quantum Physics · Physics 2023-02-14 Marcin Łobejko

A fundamental problem in quantum thermodynamics is to properly quantify the work extractable from out-of-equilibrium systems. While for closed systems, maximum quantum work extraction is defined in terms of the ergotropy functional, this…

Quantum Physics · Physics 2024-10-22 Riccardo Castellano , Donato Farina , Vittorio Giovannetti , Antonio Acin

We show that the maximum extractable work (ergotropy) from a quantum many-body system is constrained by local athermality of an initial state and local entropy decrease brought about by quantum operations. The obtained universal upper bound…

Quantum Physics · Physics 2025-01-31 Akihiro Hokkyo , Masahito Ueda

Quantifying the ergotropy (a.k.a. available energy), namely the maximal amount of energy that can be extracted from a thermally isolated system, is a central problem in quantum thermodynamics. Notably, the same problem has been long studied…

Statistical Mechanics · Physics 2026-05-19 Michele Campisi

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…

Quantum Physics · Physics 2025-05-15 Josep Lumbreras , Ruo Cheng Huang , Yanglin Hu , Mile Gu , Marco Tomamichel

As quantum technologies advance, the ability to generate increasingly large quantum states has experienced rapid development. In this context, the verification and estimation of large entangled systems represents one of the main challenges…

Quantum Physics · Physics 2022-03-30 Joshua Morris , Valeria Saggio , Aleksandra Gočanin , Borivoje Dakić

We propose a physical scheme of a uniformly accelerated Unruh-DeWitt battery and utilize quantum work extraction as a probe to witness the thermal nature of the Unruh effect induced by the accelerated motion. By employing the open quantum…

General Relativity and Quantum Cosmology · Physics 2025-09-10 Wei-Wei Zhang , Tian-Xi Ren , Yin-Zhong Wu , Xiang Hao

A short introduction on quantum thermodynamics is given and three new topics are discussed: 1) Maximal work extraction from a finite quantum system. The thermodynamic prediction fails and a new, general result is derived, the ``ergotropy''.…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 A. E. Allahverdyan , R. Balian , Th. M. Nieuwenhuizen

We characterize the impact that the application of two maps in a quantum-controlled order has on the process of work extraction via unitary cycles and its optimization. The control is based on the quantum switch model that applies maps in…

Quantum Physics · Physics 2022-04-01 Kyrylo Simonov , Gianluca Francica , Giacomo Guarnieri , Mauro Paternostro

We consider the amount of work which can be extracted from a heat bath using a bipartite state shared by two parties. In general it is less then the amount of work extractable when one party is in possession of the entire state. We derive…

Quantum Physics · Physics 2009-11-07 Jonathan Oppenheim , Michal Horodecki , Pawel Horodecki , Ryszard Horodecki