Exact density matrix of the Gutzwiller wave function as the ground state of the inverse-square supersymmetric t-J model. II. Minority spin component

The density matrix, i.e., the Fourier transform of the momentum distribution, is obtained analytically for all values of the magnetization of the Gutzwiller wave function in one dimension with the exclusion of double occupancy per site. The present result complements the previous analytic derivation of the density matrix for the majority spin. The derivation makes use of a determinantal form of the squared wave function, and multiple integrals over particle coordinates are performed with the help of a diagrammatic representation. In the thermodynamic limit, the density matrix at distance x is completely characterized by quantities vc x and vs x, where vs and vc are spin and charge velocities in the supersymmetric t-J model for which the Gutzwiller wave function gives the exact ground state. The present result then gives the exact density matrix of the t-J model for all densities and all magnetization at zero temperature. Discontinuity, slope, and curvature singularities in the momentum distribution are identified. The momentum distribution obtained by numerical Fourier transform is in excellent agreement with existing results.