An integrable chain of electrons with an impurity

Natan Andrei, Henrik Johannesson

Andrei A. Zvyagin

The exact solution of an integrable model with a magnetic (hybridization) impurity located at the edge of an open correlated electron chain is presented. It is argued that in the case when the impurity is connected to the host via a ``weak link'' its low-energy behavior coincides with that of an impurity in a periodic chain. The effects from impurities and boundary potentials are analyzed and compared.

Ana Lopez, Manuel Fuentes, Eduardo Fradkin

Z. N Hu, F. C Pu

The Kondo problem of two impurities in a 1D strongly correlated electron system within the framework of the open boundary Hubbard chain is solved and the impurities, coupled to the ends of the electron system, are introduced by their scattering matrices with electrons so that the boundary matrices satisfy the reflecting integrability condition. The finite-size correction of the ground-state energy is obtained due to the impurities. Exact expressions for the low-temperature specific heat contributed by the charge and spin parts of the magnetic impurities are derived. The Pauli susceptibility and the Kondo temperature are given explicitly. The Kondo temperature is inversely proportional to the density of electrons.

G. Benfatto, Guido Gentile, Vieri Mastropietro

Günther Ludwig