Let p1,p2 be two density matrices and M be a real, symmetric matrix.(adsbygoogle = window.adsbygoogle || []).push({});

Now,

<<p1|[M,p2]>>=

<<p1|M*p2>>-<<p1|p2*M>>=

Tr{p1*M*p2}-Tr{p1*p2*M}=

2i*Tr{(Im(p1|M*p2))}.

Why is it that this works out as simply as (x+iy)-(x-iy)?

How is Tr{p1*p2*m}=conjugate(Tr{p1*M*p2})? I can't seem to figure

out why this works out so cleanly. Thanks for any comments.

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# Commutator of a density matrix and a real symmetric matix

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