BOUNDARY SUSCEPTIBILITIES OF THE HUBBARD-MODEL IN OPEN CHAINS

Boundary contributions to the magnetization and the electron density a re evaluated analytically, near the half-filling and non-magnetic regi on. Boundary susceptibilities in the spin and the charge sectors are a lso calculated. The boundary magnetization approaches zero logarithmic ally as the magnetic field goes to zero. The boundary charge susceptib ility diverges like the bulk compressibility when the filling goes to unity.