The arguments of Cohen [Phys. Rev. A 60, 80 (1999)] against the "ignorance interpretation" of mixed states are questioned. The physical arguments are shown to be inconsistent and the supporting example illustrates the opposite of the original statement. The operational difference between two possible definitions of mixed states is exposed and the inadequacy of one of them is stressed.
|Number of pages||3|
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - 2001|