Kagan, M.Yu.; Val’kov, V.V.; Woelfle, P.
(Физика низких температур, 2011)
We consider the 2D Hubbard model in the strong-coupling case (U >> W) and at low electron density (nd² << 1). We find an antibound state as a pole in the two-particle T-matrix. The contribution of this pole in the self-energy ...