Another, equivalent, criterion is that the von Neumann entropy is 0 for a pure state, and strictly positive for a mixed state.
42.
This appears to be a reasonable assumption, as a density matrix is sufficient to describe both pure and mixed states in quantum mechanics.
43.
The family of mixed states is a convex set and a state is pure if it is an extremal point of that set.
44.
Extending the definition of separability from the pure case, we say that a mixed state is separable if it can be written as
45.
For instance, in a strong inhomogeneous magnetic field will separate out atoms in the higher energy state from a beam of mixed state atoms.
46.
Examples include a entangled, then each subsystem must be treated as a mixed state even if the complete system is in a pure state.
47.
In the mixed state, a number of tactics may be employed, such as attempting to retrieve the second disc before making an offensive play.
48.
Although here we work with mixed states, a broadcasting machine would have to work on any pure state ensemble of \ rho _ 1.
49.
When the incident beam is represented by a quantum pure state, the split beams downstream of the two slits are represented as a mixed state.
50.
Convex linear combinations of rays naturally give rise to density matrix which ( still in case of an irreducible representation ) correspond to mixed states.