Suppression of finite-size effects in one-dimensional correlated systems

We investigate the effect of a nonuniform deformation applied to one-dimensional (1D) quantum systems, where the local energy scale is proportional to g{sub j}=[sin(j{pi}/N)]{sup m} determined by a positive integer m, site index 1{ =}2, the leading 1/N correction to the ground-state energy per bond e{sub 0}{sup (N)} vanishes and one is left with a 1/N{sup 2} correction, the same as with periodic boundary conditions. In particular, when m=2, the value of e{sub 0}{sup (N)} obtained from the deformed open-boundary system coincides with the uniform system with periodic boundary conditions. We confirm the fact numerically for correlated systems, such as the extended Hubbard model, in addition to 1D free-fermion models.