Maximal work extraction from finite quantum systems
TLDR
In this article, the maximum extractable work compatible with quantum mechanics was derived and expressed in terms of the density matrix and the Hamiltonian, which is related to the property of majorization: more major states can provide more work.Abstract:
Thermodynamics teaches that if a system initially off-equilibrium is coupled to work sources, the maximum work that it may yield is governed by its energy and entropy. For finite systems this bound is usually not reachable. The maximum extractable work compatible with quantum mechanics ("ergotropy") is derived and expressed in terms of the density matrix and the Hamiltonian. It is related to the property of majorization: more major states can provide more work. Scenarios of work extraction that contrast the thermodynamic intuition are discussed, e.g. a state with larger entropy than another may produce more work, while correlations may increase or reduce the ergotropy.read more
Citations
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Journal ArticleDOI
Quantum Thermodynamics
Sai Vinjanampathy,Janet Anders +1 more
TL;DR: Quantum thermodynamics is an emerging research field aiming to extend standard thermodynamics and non-equilibrium statistical physics to ensembles of sizes well below the thermodynamic limit.
Journal ArticleDOI
Description of quantum coherence in thermodynamic processes requires constraints beyond free energy.
TL;DR: It is shown that free energy relations cannot properly describe quantum coherence in thermodynamic processes, and it is found that coherence transformations are always irreversible.
Journal ArticleDOI
Work extraction and thermodynamics for individual quantum systems
TL;DR: It is proved that the second law of thermodynamics holds in this framework, and a simple protocol is given to extract the optimal amount of work from the system, equal to its change in free energy.
Journal ArticleDOI
Equivalence of Quantum Heat Machines, and Quantum-Thermodynamic Signatures
TL;DR: Theoretically, all different engine types become thermodynamically equivalent in the quantum regime as mentioned in this paper, and it has been shown that the quantum engine types are similar to their macroscopic classical counterparts.
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Entanglement boost for extractable work from ensembles of quantum batteries.
Robert Alicki,Mark Fannes +1 more
TL;DR: It is shown that entangling unitary controls extract in general more work than independent ones, and in the limit of a large number of copies one can reach the thermodynamical bound given by the variational principle for the free energy.
References
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Book
Inequalities: Theory of Majorization and Its Applications
TL;DR: In this paper, Doubly Stochastic Matrices and Schur-Convex Functions are used to represent matrix functions in the context of matrix factorizations, compounds, direct products and M-matrices.
Journal ArticleDOI
Passive states and KMS states for general quantum systems
TL;DR: In this paper, the authors characterized equilibrium states of quantum systems by a condition of passivity suggested by the second principle of thermodynamics, and proved that ground states and β-KMS states for all inverse temperatures β≧0 are completely passive.
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A quantum-mechanical heat engine operating in finite time. A model consisting of spin-1/2 systems as the working fluid
Eitan Geva,Ronnie Kosloff +1 more
TL;DR: In this paper, the finite-time operation of a quantum-mechanical heat engine with a working fluid consisting of many noninteracting spin-1/2 systems is considered.
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Thermodynamical Proof of the Gibbs Formula for Elementary Quantum Systems
TL;DR: In this paper, an elementary derivation of the formula for the thermal equilibrium states of quantum systems that can be described in finite-dimensional Hilbert spaces is given, and three assumptions made, Passivity, Structural Stability, and Consistency, have phenomenological interpretations.