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Certifying Nonclassical Behavior for Negative Keldysh Quasiprobabilities

Potts, Patrick P. LU orcid (2019) In Physical Review Letters 122(11).
Abstract

We introduce an experimental test for ruling out classical explanations for the statistics obtained when measuring arbitrary observables at arbitrary times using individual detectors. This test requires some trust in the measurements, represented by a few natural assumptions on the detectors. In quantum theory, the considered scenarios are well captured by von Neumann measurements. These can be described naturally in terms of the Keldysh quasiprobability distribution (KQPD), and the imprecision and backaction exerted by the measurement apparatus. We find that classical descriptions can be ruled out from measured data if and only if the KQPD exhibits negative values. We provide examples based on simulated data, considering the influence... (More)

We introduce an experimental test for ruling out classical explanations for the statistics obtained when measuring arbitrary observables at arbitrary times using individual detectors. This test requires some trust in the measurements, represented by a few natural assumptions on the detectors. In quantum theory, the considered scenarios are well captured by von Neumann measurements. These can be described naturally in terms of the Keldysh quasiprobability distribution (KQPD), and the imprecision and backaction exerted by the measurement apparatus. We find that classical descriptions can be ruled out from measured data if and only if the KQPD exhibits negative values. We provide examples based on simulated data, considering the influence of a finite amount of statistics. In addition to providing an experimental tool for certifying nonclassicality, our results bestow an operational meaning upon the nonclassical nature of negative quasiprobability distributions such as the Wigner function and the full counting statistics.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review Letters
volume
122
issue
11
article number
110401
publisher
American Physical Society
external identifiers
  • pmid:30951341
  • scopus:85063274666
ISSN
0031-9007
DOI
10.1103/PhysRevLett.122.110401
language
English
LU publication?
yes
id
6669ea3f-d8f0-4ed8-8564-a641ec7e0b03
date added to LUP
2019-04-02 08:42:01
date last changed
2024-02-14 20:56:03
@article{6669ea3f-d8f0-4ed8-8564-a641ec7e0b03,
  abstract     = {{<p>We introduce an experimental test for ruling out classical explanations for the statistics obtained when measuring arbitrary observables at arbitrary times using individual detectors. This test requires some trust in the measurements, represented by a few natural assumptions on the detectors. In quantum theory, the considered scenarios are well captured by von Neumann measurements. These can be described naturally in terms of the Keldysh quasiprobability distribution (KQPD), and the imprecision and backaction exerted by the measurement apparatus. We find that classical descriptions can be ruled out from measured data if and only if the KQPD exhibits negative values. We provide examples based on simulated data, considering the influence of a finite amount of statistics. In addition to providing an experimental tool for certifying nonclassicality, our results bestow an operational meaning upon the nonclassical nature of negative quasiprobability distributions such as the Wigner function and the full counting statistics.</p>}},
  author       = {{Potts, Patrick P.}},
  issn         = {{0031-9007}},
  language     = {{eng}},
  month        = {{03}},
  number       = {{11}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review Letters}},
  title        = {{Certifying Nonclassical Behavior for Negative Keldysh Quasiprobabilities}},
  url          = {{http://dx.doi.org/10.1103/PhysRevLett.122.110401}},
  doi          = {{10.1103/PhysRevLett.122.110401}},
  volume       = {{122}},
  year         = {{2019}},
}