A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Amount of quantum coherence needed for measurement incompatibility
Tekijät: Kiukas Jukka, McNulty Daniel, Pellonpää Juha-Pekka
Kustantaja: AMER PHYSICAL SOC
Julkaisuvuosi: 2022
Journal: Physical Review A
Tietokannassa oleva lehden nimi: PHYSICAL REVIEW A
Lehden akronyymi: PHYS REV A
Artikkelin numero: 012205
Vuosikerta: 105
Numero: 1
Sivujen määrä: 18
ISSN: 2469-9926
eISSN: 2469-9934
DOI: https://doi.org/10.1103/PhysRevA.105.012205
Verkko-osoite: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.105.012205
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/174767829
A pair of quantum observables diagonal in the same "incoherent" basis can be measured jointly, so some coherence is obviously required for measurement incompatibility. Here we first observe that coherence in a single observable is linked to the diagonal elements of any observable jointly measurable with it, leading to a general criterion for the coherence needed for incompatibility. Specializing to the case where the second observable is incoherent (diagonal), we develop a concrete method for solving incompatibility problems, tractable even in large systems by analytical bounds, without resorting to numerical optimization. We verify the consistency of our method by a quick proof of the known noise bound for mutually unbiased bases, and apply it to study emergent classicality in the spin-boson model of an N-qubit open quantum system. Finally, we formulate our theory in an operational resource-theoretic setting involving "genuinely incoherent operations" used previously in the literature, and show that if the coherence is insufficient to sustain incompatibility, the associated joint measurements have sequential implementations via incoherent instruments.
Ladattava julkaisu This is an electronic reprint of the original article. |  |
