Inspection of the Density Matrix

Lamont1986 · Mar 31, 2010

I have a question about density matrices. Is there a way to deduce the purity of the density matrix just by inspection?

-L

strangerep · Mar 31, 2010

Lamont1986 said:

I have a question about density matrices. Is there a way to deduce the purity of the density matrix just by inspection?

I don't think you can deduce it just by inspection. One needs to at least
calculate [itex]\rho^2[/itex] and check that it has unit trace.
Cf. Ballentine pp 51-52.

Inspection of the Density Matrix

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