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arXiv · 1501.03505

Non-classicality of temporal correlations

Stephen Brierley·Adrian Kosowski·Marcin Markiewicz·Tomasz Paterek·Anna Przysiezna
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Abstract

The results of space-like separated measurements are independent of distant measurement settings, a property one might call two-way no-signalling. In contrast, time-like separated measurements are only one-way no-signalling since the past is independent of the future but not vice-versa. For this reason temporal correlations that are formally identical to non-classical spatial correlations can still be modelled classically. We define non-classical temporal correlations as the ones which cannot be simulated by propagating in time a classical information content of a quantum system. We first show that temporal correlations between results of any projective quantum measurements on a qubit can be simulated classically. Then we present a sequence of POVM measurements on a single $m$-level quantum system that cannot be explained by propagating in time $m$-level classical system and using classical computers with unlimited memory.

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Stephen Brierley, Adrian Kosowski, Marcin Markiewicz, Tomasz Paterek, Anna Przysiezna. 2015-05-26. Non-classicality of temporal correlations. https://doi.org/10.1103/physrevlett.115.120404

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