A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Joint measurability in nonequilibrium quantum thermodynamics
Tekijät: Beyer Konstantin, Uola Roope, Luoma Kimmo, Strunz Walter T.
Kustantaja: AMER PHYSICAL SOC
Julkaisuvuosi: 2022
Journal: Physical review E
Lehden akronyymi: PHYS REV E
Artikkelin numero: L022101
Vuosikerta: 106
Numero: 2
Sivujen määrä: 6
ISSN: 2470-0045
eISSN: 2470-0053
DOI: https://doi.org/10.1103/PhysRevE.106.L022101
Verkko-osoite: https://journals.aps.org/pre/abstract/10.1103/PhysRevE.106.L022101
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/176476566
Preprintin osoite: https://arxiv.org/abs/2111.02854v1
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.
Ladattava julkaisu This is an electronic reprint of the original article. |