Stokes, A, Deb, P and Beige, A orcid.org/0000-0001-7230-4220 (2017) Using thermodynamics to identify quantum subsystems. Journal of Modern Optics, 64 (sup4). S7-S19. ISSN 0950-0340
Abstract
There are many ways to decompose the Hilbert space ℋ of a composite quantum system into tensor product subspaces. Different subsystem decompositions generally imply different interaction Hamiltonians V, and therefore different expectation values for subsystem observables. This means that the uniqueness of physical predictions is not guaranteed, despite the uniqueness of the total Hamiltonian H and the total Hilbert space ℋ. Here we use Clausius’ version of the second law of thermodynamics (CSL) and standard identifications of thermodynamic quantities to identify possible subsystem decompositions. It is shown that agreement with the CSL is obtained, whenever the total Hamiltonian and the subsystem-dependent interaction Hamiltonian commute (i.e. [H,V]=0). Not imposing this constraint can result in the transfer of heat from a cooler to a hotter subsystem, in conflict with thermodynamics. We also investigate the status of the CSL with respect to non-standard definitions of thermodynamic quantities and quantum subsystems.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2017, The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Keywords: | Quantum electrodynamics, quantum thermodynamics, anomalous heat flow |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Theoretical Physics (Leeds) |
Funding Information: | Funder Grant number Royal Society 2013/R3 EPSRC EP/H048901/1 EPSRC EP/M013243/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 20 Mar 2017 13:45 |
Last Modified: | 27 Jan 2018 20:18 |
Status: | Published |
Publisher: | Taylor & Francis |
Identification Number: | 10.1080/09500340.2017.1295108 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:113763 |