ONE-DIMENSIONAL T-J MODEL FROM A VARIATIONAL VIEWPOINT

The one-dimensional (1D) t-J model is investigated by using a Gutzwill er-Jastrow-type variation method and the exact diagonalization of smal l systems. Variational expectation values are estimated by the variati onal Monte Carlo method with sufficient accuracy. First, we give detai led descriptions of the preceding paper [Phys. Rev. Lett. 67, 3610 (19 91)], where we discussed the properties of the Fermi-liquid-type Jastr ow wave function as well as the Gutzwiller wave function. Secondly, th ese wave functions are compared with the Tomonaga-Luttinger-liquid-typ e wave function proposed by Hellberg and Mele. It is found that the co rrelation factors in short distances control bulk quantities like ener gy and the magnitude of the correlation functions, while the long-rang e part of the correlation factors determines the critical behavior of correlation functions. Finally, using these functions, charge, spin su sceptibilities, and magnetization curve are estimated, which agree wit h the exact results. It is shown that the Mott transition in the 1D t- J model is quite different from the Brinkman-Rice transition.