Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1906.12163 · Physical Review Letters

Steering Heat Engines: A Truly Quantum Maxwell Demon

Konstantin Beyer, Kimmo Luoma, Walter T. Strunz

Published Dec 20, 2019• 37 citations
arXivHTMLPDF

Abstract

We address the question of verifying the quantumness of thermal machines. A Szilárd engine is truly quantum if its work output cannot be described by a local hidden state model, i.e., an objective local statistical ensemble. Quantumness in this scenario is revealed by a steering-type inequality which bounds the classically extractable work. A quantum Maxwell demon can violate that inequality by exploiting quantum correlations between the work medium and the thermal environment. While for a classical Szilárd engine an objective description of the medium always exists, any such description can be ruled out by a steering task in a truly quantum case.

DOI
10.1103/physrevlett.123.250606

Related papers

A truly quantum Szil\'ard demon

Konstantin Beyer, Kimmo Luoma, Walter T. Strunz

We revisit the question of quantumness of thermal machines from a quantum information point of view. As an example we choose a one-qubit Szilard engine and ask when it can be considered to be truly quantum in the sense that the work output of the engine cannot be described by classical statistics. A truly quantum demon can exploit the correlations between the work medium and the surrounding bath. We will formulate the problem as a semi-device independent test which leads to a quantum steering scenario. While in a classical Szilard engine an objective description of the medium always exists, any such description can be ruled out by a steering task in the true quantum case.

•Jun 28, 2019•0 citations

Spin Quantum Heat Engine Quantified by Quantum Steering

Wentao Ji, Zihua Chai, Mengqi Wang +6 more

Following the rising interest in quantum information science, the extension of a heat engine to the quantum regime by exploring microscopic quantum systems has seen a boon of interest in the last decade. Although quantum coherence in the quantum system of the working medium has been investigated to play a nontrivial role, a complete understanding of the intrinsic quantum advantage of quantum heat engines remains elusive. We experimentally demonstrate that the quantum correlation between the working medium and the thermal bath is critical for the quantum advantage of a quantum Szilárd engine, where quantum coherence in the working medium is naturally excluded. By quantifying the nonclassical correlation through quantum steering, we reveal that the heat engine is quantum when the demon can truly steer the working medium. The average work obtained by taking different ways of work extraction on the working medium can be used to verify the real quantum Szilárd engine.

arXiv:2202.02009•Physical Review Letters•Mar 1, 2022•64 citations

Maxwell's demon in the quantum world

Sanguk Kim, Takahiro Sagawa, Simone De Liberato +1 more

The Szilard engine (SZE) is the quintessence of Maxwell's demon, which can extract the work from a heat bath by utilizing information. We present the first complete quantum analysis of the SZE, and derive an analytic expression of the quantum-mechanical work performed by a quantum SZE containing an arbitrary number of molecules, where it is crucial to regard the process of insertion or removal of a wall as a legitimate thermodynamic process. We find that more (less) work can be extracted from the bosonic (fermionic) SZE due to the indistinguishability of identical particles.

•Jun 8, 2010•0 citations

Maxwell’s demon in the quantum world

Juan M. R. Parrondo, Jordan M. Horowitz

The Szilard engine (SZE) is the quintessence of Maxwell's demon, which can extract the work from a heat bath by utilizing information.We present the first complete quantum analysis of the SZE, and derive an analytic expression of the quantum-mechanical work performed by a quantum SZE containing an arbitrary number of molecules, where it is crucial to regard the process of insertion or removal of a wall as a legitimate thermodynamic process.We find that more (less) work can be extracted from the bosonic (fermionic) SZE due to the indistinguishability of identical particles.

Physics•Feb 14, 2011•5 citations

Landauer’s Principle in a Quantum Szilard Engine without Maxwell’s Demon

Alhun Aydin, Altuğ Şişman, Ronnie Kosloff

Quantum Szilard engine constitutes an adequate interplay of thermodynamics, information theory and quantum mechanics. Szilard engines are in general operated by a Maxwell's Demon where Landauer's principle resolves the apparent paradoxes. Here we propose a Szilard engine setup without featuring an explicit Maxwell's demon. In a demonless Szilard engine, the acquisition of which-side information is not required, but the erasure and related heat dissipation still take place implicitly. We explore a quantum Szilard engine considering quantum size effects. We see that insertion of the partition does not localize the particle to one side, instead creating a superposition state of the particle being in both sides. To be able to extract work from the system, particle has to be localized at one side. The localization occurs as a result of quantum measurement on the particle, which shows the importance of the measurement process regardless of whether one uses the acquired information or not. In accordance with Landauer's principle, localization by quantum measurement corresponds to a logically irreversible operation and for this reason it must be accompanied by the corresponding heat dissipation. This shows the validity of Landauer's principle even in quantum Szilard engines without Maxwell's demon.

arXiv:1908.04400•Entropy•Mar 3, 2020•26 citations

Entanglement preparation and work extraction wiht a truly quantum Maxwell demon

Gang-Gang He, Fulin Zhang

The information of a quantum system acquired by a Maxwell demon can be used for either work extraction or entanglement preparation. We study these two tasks by using a thermal qubit, in which a demon obtains her information from measurements on the environment of the qubit. The allowed entanglement, between the qubit and an auxiliary system, is enhanced by the information. And, the increment is find to be equivalent to the extractable work. The Maxwell demon is called to be quantum by Beyer \textit{et al.} [Phys. Rev. Lett 123, 250606 (2019) ] if there is quantum steering from the environment to the qubit. In this case, the postmeasured states of the qubit, after the measurements on its environment, cannot be simulated by an objective local statistical ensemble. We present a upper bound of extractable work, and equivalently of the allowed entanglement, for unsteerable demons, considering two measurements inducing two orthogonal changes of the Bloch vector of the qubit.

•Mar 4, 2021•0 citations
We address the question of verifying the quantumness of thermal machines. A Szilárd engine is truly quantum if its work output cannot be described by a local hidden state model, i.e., an objective local statistical ensemble. Quantumness in this scenario is revealed by a steering-type inequality which bounds the classically extractable work. A quantum Maxwell demon can violate that inequality by exploiting quantum correlations between the work medium and the thermal environment. While for a classical Szilárd engine an objective description of the medium always exists, any such description can be ruled out by a steering task in a truly quantum case.
We revisit the question of quantumness of thermal machines from a quantum information point of view. As an example we choose a one-qubit Szilard engine and ask when it can be considered to be truly quantum in the sense that the work output of the engine cannot be described by classical statistics. A truly quantum demon can exploit the correlations between the work medium and the surrounding bath. We will formulate the problem as a semi-device independent test which leads to a quantum steering scenario. While in a classical Szilard engine an objective description of the medium always exists, any such description can be ruled out by a steering task in the true quantum case.
Following the rising interest in quantum information science, the extension of a heat engine to the quantum regime by exploring microscopic quantum systems has seen a boon of interest in the last decade. Although quantum coherence in the quantum system of the working medium has been investigated to play a nontrivial role, a complete understanding of the intrinsic quantum advantage of quantum heat engines remains elusive. We experimentally demonstrate that the quantum correlation between the working medium and the thermal bath is critical for the quantum advantage of a quantum Szilárd engine, where quantum coherence in the working medium is naturally excluded. By quantifying the nonclassical correlation through quantum steering, we reveal that the heat engine is quantum when the demon can truly steer the working medium. The average work obtained by taking different ways of work extraction on the working medium can be used to verify the real quantum Szilárd engine.
The Szilard engine (SZE) is the quintessence of Maxwell's demon, which can extract the work from a heat bath by utilizing information. We present the first complete quantum analysis of the SZE, and derive an analytic expression of the quantum-mechanical work performed by a quantum SZE containing an arbitrary number of molecules, where it is crucial to regard the process of insertion or removal of a wall as a legitimate thermodynamic process. We find that more (less) work can be extracted from the bosonic (fermionic) SZE due to the indistinguishability of identical particles.
The Szilard engine (SZE) is the quintessence of Maxwell's demon, which can extract the work from a heat bath by utilizing information.We present the first complete quantum analysis of the SZE, and derive an analytic expression of the quantum-mechanical work performed by a quantum SZE containing an arbitrary number of molecules, where it is crucial to regard the process of insertion or removal of a wall as a legitimate thermodynamic process.We find that more (less) work can be extracted from the bosonic (fermionic) SZE due to the indistinguishability of identical particles.
Quantum Szilard engine constitutes an adequate interplay of thermodynamics, information theory and quantum mechanics. Szilard engines are in general operated by a Maxwell's Demon where Landauer's principle resolves the apparent paradoxes. Here we propose a Szilard engine setup without featuring an explicit Maxwell's demon. In a demonless Szilard engine, the acquisition of which-side information is not required, but the erasure and related heat dissipation still take place implicitly. We explore a quantum Szilard engine considering quantum size effects. We see that insertion of the partition does not localize the particle to one side, instead creating a superposition state of the particle being in both sides. To be able to extract work from the system, particle has to be localized at one side. The localization occurs as a result of quantum measurement on the particle, which shows the importance of the measurement process regardless of whether one uses the acquired information or not. In accordance with Landauer's principle, localization by quantum measurement corresponds to a logically irreversible operation and for this reason it must be accompanied by the corresponding heat dissipation. This shows the validity of Landauer's principle even in quantum Szilard engines without Maxwell's demon.
The information of a quantum system acquired by a Maxwell demon can be used for either work extraction or entanglement preparation. We study these two tasks by using a thermal qubit, in which a demon obtains her information from measurements on the environment of the qubit. The allowed entanglement, between the qubit and an auxiliary system, is enhanced by the information. And, the increment is find to be equivalent to the extractable work. The Maxwell demon is called to be quantum by Beyer \textit{et al.} [Phys. Rev. Lett 123, 250606 (2019) ] if there is quantum steering from the environment to the qubit. In this case, the postmeasured states of the qubit, after the measurements on its environment, cannot be simulated by an objective local statistical ensemble. We present a upper bound of extractable work, and equivalently of the allowed entanglement, for unsteerable demons, considering two measurements inducing two orthogonal changes of the Bloch vector of the qubit.