Exact soultion of asymmetric diffusion with second-class particles of arbitrary size

The exact solution of the asymmetric exclusion problem with particles of first and second class is presented. In this model the particles (size 1) of both classes are attached on lattice points and diffuse with equal asymmetric rates, but particles in the first class do not distinguish those in the second class from the holes (empty sites). We generalize and solve exactly this model by considering molecules in the first and second class with sizes $s_1$ and $s_2$ ($s_1,s_2 = 0,1,2,...$), in units of lattice spacing, respectively. The solution is derived by a Bethe ansatz of nested type. We give in this paper a pedagogical and simple presentation of the Bethe ansatz solution of the problem which can easily be followed by a non specialized audience in exactly integrable models.Comment: 21 pages, 7 figure

Exact Solution of Asymmetric Diffusion With N Classes of Particles of Arbitrary Size and Hierarchical Order

The exact solution of the asymmetric exclusion problem with N distinct classes of particles (c = 1,2,...,N), with hierarchical order is presented. In this model the particles (size 1) are located at lattice points, and diffuse with equal asymmetric rates, but particles in a class c do not distinguish those in the classes c' >c from holes (empty sites). We generalize and solve exactly this model by considering the molecules in each distinct class c =1,2,...,N with sizes s_c (s_c = 0,1,2,...), in units of lattice spacing. The solution is derived by a Bethe ansatz of nested type.Comment: 27 pages, 1 figur

Interpolation between Hubbard and supersymmetric t-J models. Two-parameter integrable models of correlated electrons

Two new one-dimensional fermionic models depending on two independent parameters are formulated and solved exactly by the Bethe-ansatz method. These models connect continuously the integrable Hubbard and supersymmetric t-J models.Comment: 11pages and no figure

Exact Solution of a Vertex Model with Unlimited Number of States Per Bond

The exact solution is obtained for the eigenvalues and eigenvectors of the row-to-row transfer matrix of a two-dimensional vertex model with unlimited number of states per bond. This model is a classical counterpart of a quantum spin chain with an unlimited value of spin. This quantum chain is studied using general predictions of conformal field theory. The long-distance behaviour of some ground-state correlation functions is derived from a finite-size analysis of the gapless excitations.Comment: 11pages, 6 figure

Integrable model of interacting XX and Fateev-Zamolodchikov chains

We consider the exact solution of a model of correlated particles, which is presented as a system of interacting XX and Fateev-Zamolodchikov chains. This model can also be considered as a generalization of the multiband anisotropic $t-J$ model in the case we restrict the site occupations to at most two electrons. The exact solution is obtained for the eigenvalues and eigenvectors using the Bethe-ansatz method.Comment: 10 pages, no figure

New Integrable Models of Strongly Correlated Particles with Correlated Hopping

The exact solution is obtained for the eigenvalues and eigenvectors for two models of strongly correlated particles with single-particle correlated and uncorrelated pair hoppings. The asymptotic behavior of correlation functions are analysed in different regions, where the models exhibit different physical behavior.Comment: 12 pages, 3 figure

Exactly Solvable Interacting Spin-Ice Vertex Model

A special family of solvable five-vertex model is introduced on a square lattice. In addition to the usual nearest neighbor interactions, the vertices defining the model also interact alongone of the diagonals of the lattice. Such family of models includes in a special limit the standard six-vertex model. The exact solution of these models gives the first application of the matrix product ansatz introduced recently and applied successfully in the solution of quantum chains. The phase diagram and the free energy of the models are calculated in the thermodynamic limit. The models exhibit massless phases and our analyticaland numerical analysis indicate that such phases are governed by a conformal field theory with central charge $c=1$ and continuosly varying critical exponents.Comment: 14 pages, 11 figure