Or, would it make more sense to think about coherence between two symmetric-asymmetric (Dicke basis or so called singlet-triplet states of composite system) states?
Even when we start in a density matrix that is product of individual ones, (non)unitary evolution may complicate things by making...
My question is about generalization of most simple problem in semi-classical quantum optics. Composite system of two-level systems.
single system's diagram: http://ars.sciencedirect.com/content/image/1-s2.0-S0030401807009777-gr1.jpg
where atomic frequency: wab=wa - wa; probing frequency...