### Abstract

A recent paper by Souza, Oliveira and Sarthour (SOS) reports the experimental violation of a Leggett-Garg (LG) inequality (sometimes referred to as a temporal Bell inequality). The inequality tests for quantum mechanical superposition: if the inequality is violated, the dynamics cannot be explained by a large class of classical theories under the heading of macrorealism. Experimental tests of the LG inequality are beset by the difficulty of carrying out the necessary so-called 'non-invasive' measurements (which for the macrorealist will extract information from a system of interest without disturbing it). SOS argue that they nevertheless achieve this difficult goal by putting the system in a maximally mixed state. The system then allegedly undergoes no perturbation during their experiment. Unfortunately, the method is ultimately unconvincing to a skeptical macrorealist and so the conclusions drawn by SOS are unjustified.

Original language | English |
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Article number | 058001 |

Number of pages | 6 |

Journal | New Journal of Physics |

Volume | 14 |

DOIs | |

Publication status | Published - 9 May 2012 |

## Cite this

*New Journal of Physics*,

*14*, [058001]. https://doi.org/10.1088/1367-2630/14/5/058001