Binding of holons and spinons in the one-dimensional anisotropic t-J model
arXiv:cond-mat/0702213 · doi:10.1103/PhysRevLett.98.266401
Abstract
We study the binding of a holon and a spinon in the one-dimensional anisotropic t-J model using a Bethe-Salpeter equation approach, exact diagonalization, and density matrix renormalization group methods on chains of up to 128 sites. We find that holon-spinon binding changes dramatically as a function of anisotropy parameter α=J_\perp/J_z: it evolves from an exactly deducible impurity-like result in the Ising limit to an exponentially shallow bound state near the isotropic case. A remarkable agreement between the theory and numerical results suggests that such a change is controlled by the corresponding evolution of the spinon energy spectrum.
4 pages, 5 figures, published version