Recent content by Toten

Thank you! I hadn't realize that the determinant of the density matrix is zero. This gave me an idea on how to reorganize the terms in the following expression: |a|^2 x |c|^2 + |b|^2 x |d|^2 + ab*c*d + a*bcd* = aa*cc* + bb*dd* + ab*c*d + a*bcd* = ac*a*c + bd*b*d + ac*b*d + bd*a*c = ac*(a*c...

Even if the density matrix is defined for a ensemble of spinors, the property holds true. How can you prove it?

Hello. I need some help to prove the first property of the density matrix for a pure state. According to this property, the density matrix is definite positive (or semi-definite positive). I've been trying to prove it mathematically, but I can't. I need to prove that |a|^2 x |c|^2 +...