A1 Refereed original research article in a scientific journal

Joint measurability in nonequilibrium quantum thermodynamics




AuthorsBeyer Konstantin, Uola Roope, Luoma Kimmo, Strunz Walter T.

PublisherAMER PHYSICAL SOC

Publication year2022

JournalPhysical review E

Journal acronymPHYS REV E

Article number L022101

Volume106

Issue2

Number of pages6

ISSN2470-0045

eISSN2470-0053

DOIhttps://doi.org/10.1103/PhysRevE.106.L022101

Web address https://journals.aps.org/pre/abstract/10.1103/PhysRevE.106.L022101

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/176476566

Preprint addresshttps://arxiv.org/abs/2111.02854v1


Abstract

In this Letter we investigate the concept of quantum work and its measurability from the viewpoint of quantum measurement theory. Very often, quantum work and fluctuation theorems are discussed in the framework of projective two-point measurement (TPM) schemes. According to a well-known no-go theorem, there is no work observable which satisfies both (i) an average work condition and (ii) the TPM statistics for diagonal input states. Such projective measurements represent a restrictive class among all possible measurements. It is desirable, both from a theoretical and experimental point of view, to extend the scheme to the general case including suitably designed unsharp measurements. This shifts the focus to the question of what information about work and its fluctuations one is able to extract from such generalized measurements. We show that the no-go theorem no longer holds if the observables in a TPM scheme are jointly measurable for any intermediate unitary evolution. We explicitly construct a model with unsharp energy measurements and derive bounds for the visibility that ensure joint measurability. In such an unsharp scenario a single work measurement apparatus can be constructed that allows us to determine the correct average work and to obtain free energy differences with the help of a Jarzynski equality.


Downloadable publication

This is an electronic reprint of the original article.
This reprint may differ from the original in pagination and typographic detail. Please cite the original version.





Last updated on 2024-26-11 at 22:54