Nonlinear electrostatic response of strongly correlated one-dimensional electron systems

We investigate the nonlinear response of the strongly correlated one-dimensional electron systems to the static electric field with using the one-dimensional Hubbard model in the half-filled case. We adopt the variational Monte Carlo method with the Gutzwiller wave function to describe the strong correlation effects. In the weak correlation region U/t <= 4, where U is the one-site Coulomb repulsion energy and t is the transfer integral between the nearest neighbor sites, the response can be described within the band picture, and the third order nonlinear susceptibility chi((3)) increases slowly with increasing U/t. For U/t <= 4, chi((3)) increases rapidly with increasing U/t, and chi((3)) at U/t = 10 is more than ten times larger than that at U/t = 2. This large value of chi((3)) originates from the exotic properties of carriers in the strongly correlated one-dimensional electron systems. (c) 2005 Elsevier Ltd. All rights reserved.