Comment on ‘‘Theorem on nonclassical states’’

Abstract

In a recent paper, C. T. Lee [ Phys. Rev. A 52, 3374 (1995) ] showed that if \ensuremath{\rho}^=${\ensuremath{\sum}}_{\mathit{n},\mathit{m}}$\ensuremath{\rho}(n,m)|n〉〈m| is the density operator describing an arbitrary state, with \ensuremath{\rho}(0,0)=〈0|\ensuremath{\rho}^|0〉=0, the state is as nonclassical as possible. Here we exhibit an example in apparent contradiction with the above theorem. \textcopyright{} 1996 The American Physical Society.