Vogel W
Arbeitsgruppe Quantenoptik, Fachbereich Physik, Universitat Rostock, Universitatsplatz 3, D-18051 Rostock, Germany.
Phys Rev Lett. 2000 Feb 28;84(9):1849-52. doi: 10.1103/PhysRevLett.84.1849.
An observable criterion is derived that allows one to distinguish nonclassical states of the harmonic oscillator from those having a classical counterpart. A quantum state is shown to have no classical counterpart if and only if the characteristic functions of the quadrature distributions or the s-parametrized phase-space distributions exhibit a slower decay than for the ground state of the oscillator. This renders it possible to experimentally check the failure of the P function to be a probability measure.
推导出一个可观测准则，该准则能让人区分谐振子的非经典态与具有经典对应态的状态。结果表明，当且仅当正交分布或s参数化相空间分布的特征函数呈现出比振子基态更慢的衰减时，量子态才没有经典对应态。这使得通过实验检验P函数作为概率测度的失效成为可能。
