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arXiv · 1506.00519

Optimal violation of Leggett-Garg inequality for arbitrary spin and emergence of classicality through unsharp measurement

Shiladitya Mal·A. S Majumdar
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Abstract

We consider temporal correlations of particles with arbitrary spin. We show that the Leggett-Garg inequality can be maximally violated irrespective of the value of spin, thus improving upon an earlier result by Kofler and Brukner [Phys. Rev. Lett. \textbf{99}, 180403 (2007)]. Our proof is accomplished through a suitable adoption of a measurement scheme which has previously been employed for studying the spatial correlation in a system with arbitrary spin. We next consider generalized or unsharp measurements as a method for coarse graining in a quantitative manner, and show that classicality emerges below a precise value of the sharpness parameter. Satisfaction of the Leggett-Garg inequality is shown to be a necessary and sufficient condition for macroscopic realism.

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Shiladitya Mal, A. S Majumdar. 2015-09-26. Optimal violation of Leggett-Garg inequality for arbitrary spin and emergence of classicality through unsharp measurement. https://doi.org/10.1016/j.physleta.2016.05.020

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