Off-diagonal elements in a density matrix

[CarvalhoGD]

Hello everyone,

I have a math / physics question that has been with me for a while. I would be grateful if someone could help me.

Given a density matrix, what is the minimum value a sum of some of its off-diagonal elements can assume (or the most negative value)?
Remark: if one collect an off-diagonal element to compose the sum, its complex conjugate will also compose the sum.

Thank you.

 

[troglodyte]

Sorry,but I don't understand your question not good enough to give you an answer.Try to make your question a little bit more concrete.Maybe you should post the reference where question is related to.