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arXiv · 0706.0668

The conditions for quantum violation of macroscopic realism

Johannes Kofler·Caslav Brukner
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Abstract

Why do we not experience a violation of macroscopic realism in every-day life? Normally, no violation can be seen either because of decoherence or the restriction of coarse-grained measurements, transforming the time evolution of any quantum state into a classical time evolution of a statistical mixture. We find the sufficient condition for these classical evolutions for spin systems under coarse-grained measurements. Then we demonstrate that there exist "non-classical" Hamiltonians whose time evolution cannot be understood classically, although at every instant of time the quantum spin state appears as a classical mixture. We suggest that such Hamiltonians are unlikely to be realized in nature because of their high computational complexity.

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Johannes Kofler, Caslav Brukner. 2008-08-28. The conditions for quantum violation of macroscopic realism. https://doi.org/10.1103/physrevlett.101.090403

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