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.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Commutator of a density matrix and a real symmetric matix

**Physics Forums | Science Articles, Homework Help, Discussion**