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arXiv · 1506.04993

Modeling Leggett-Garg-inequality violation

Saulo V. Moreira·Arne Keller·Thomas Coudreau·Perola Milman
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Abstract

The Leggett-Garg inequality is a widely used test of the "quantumness" of a system, and involves correlations between measurements realized at different times. According to its widespread interpretation, a violation of the Legget-Garg inequality disproofs macroscopic realism and non-invasiveness. Nevertheless, recent results point out that macroscopic realism is a model dependent notion and that one should always be able to attribute to invasiveness a violation of a Legget-Garg inequality. This opens some natural questions: how to provide such an attribution in a systematic way? How can apparent macroscopic realism violation be recast into a dimensional independent invasiveness model? The present work answers these questions by introducing an operational model where the effects of invasiveness are controllable through a parameter associated with what is called the {\it measurability} of the physical system. Such a parameter leads to different generalized measurements that can be associated with the dimensionality of a system, to measurement errors or to back action.

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Saulo V. Moreira, Arne Keller, Thomas Coudreau, Perola Milman. 2016-01-06. Modeling Leggett-Garg-inequality violation. https://doi.org/10.1103/physreva.92.062132

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