a) I would like to ask, if knowledge about eigenvectors in second quantization is important and what do they mean? Let's just say, I create Fock space [(NumberOfSites)x(Permutations) matrix], then I solve Hubbard Hamiltonian [(NumberOfSites)x(NumberOfSites) matrix]. After diagonalisation of this Hamiltonian I get eigenvalues [Energies] and eigenvectors.How should I interpret these eigenvectors?
b) How can I know/calculate what phase does system has? Basically, how is someone able to tell which phase does system has just from Hamiltonian?