Let P be a density matrix. Then the von neumann entropy is defined as(adsbygoogle = window.adsbygoogle || []).push({});

S(P) = -tr(P*log(P))

But how is log(P) defined ?

--edit--

found the answer. the trace is independent of representation so that if P is diagonalized with eigenvalues {k} then S(P) = H({k}) where H is the shannon entropy.

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# Von neumann entropy, log(P) ?

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