Pairing Mechanism in the doped Hubbard Antiferromagnet: the $4\times 4$ Model as a Test Case

Michele Cini, Enrico Perfetto, Gianluca Stefanucci

We introduce a {\em local} formalism, in terms of eigenstates of number operators, having well defined point symmetry, to solve the Hubbard model at weak coupling on a $N\times N$…