Measures of macroscopicity for quantum spin systems
arXiv:1205.3048 · doi:10.1088/1367-2630/14/9/093039
Abstract
We investigate the notion of "macroscopicity" in the case of large quantum spin systems and provide two main results. First, we motivate the Fisher information as a measure for the macroscopicity of quantum states. Second, we compare the existing literature of this topic. We report on a hierarchy among the measures and we conclude that one should carefully distinguish between "macroscopic quantum states" and "macroscopic superpositions", which is a strict subclass of the former.
Comments are welcome! v2: Minor improvements of the text