Related papers: Spin-Gap Phase in the One-Dimensional t-J-J' Model

We give the details of the analysis for critical properties of spin-gap phases in one-dimensional lattice electron models. In the Tomonaga-Luttinger (TL) liquid theory, the spin-gap instability occurs when the backward scattering changes…

We study the one-dimensional deformed $t-t^{\prime}-J$ model in terms of the continuum field theories. We found that at low doping concentration and far away from the phase separation regime, there are two phases: the Luttinger liquid and…

We discuss the possible existence of a spin-gap phase in the low-doping regime of strongly-correlated two-dimensional electrons within the gauge field description of the t-J model. The spin-gap phase was recently shown by Ubbens and Lee to…

We examine the effect of spin gap on single-hole spectral function in the one-dimensional t-J-J'model. At J'/J=1/2, where a dimer state is the ground state, an analytic expression is derived for J/t \to 0. At finite values of J/t, the…

The spin and charge excitations of the t--J ladder are studied by exact diagonalization techniques for several electron densities. The various modes are classified according to their spin (singlet or triplet excitations) and their parity…

We examine the ground-state phase diagram of the t-J model in one dimension by means of the Density Matrix Renormalization Group. This model is characterized by a rich phase diagram as a function of the exchange interaction J and the…

The recursion method is used to determine the T=0 spin dynamic structure factor S_{zz}(q,\omega) in the Luttinger liquid state and in the phase-separated state of the one-dimensional t-J model. As the exchange coupling increases from zero,…

The impact of the spin-flip terms on the (static and dynamic) charge and spin correlations in the Luttinger-liquid ground state of the 1D $t-J$ model is assessed by comparison with the same quantities in the 1D $t-J_z$ model, where…

We propose a correlated spin-singlet-pairs wave function to describe the spin-gap phase of the one-dimensional $t-J$ model at low density. Adding a Jastrow factor with a variational parameter, $\nu$, first introduced by Hellberg and Mele,…

We use the coupled cluster method implemented at high orders of approximation to study the spin-$\frac{1}{2}$ $J_{1}$--$J_{2}$ model on the triangular lattice with Heisenberg interactions between nearest-neighbour and next-nearest-neighbour…

We investigate the thermodynamics of the one-dimensional t-J model using transfer matrix renormalization group (TMRG) algorithms and present results for quantities like particle number, specific heat, spin susceptibility and…

We study the one-dimensional t-J-J'-model in the limit of small hole doping $x$ and small $J/t$, $J'/t$. Special emphasis is put on the regime $J'/J \approx .5$ where a spin gap is present at small doping and the undoped spin chain is…

Spin gaps in coupled $t$-$J$ ladders are investigated by exact diagonalization of small clusters up to 4$\times$8 sites. At half-filling, the numerical results for the triplet excitation spectrum are in very good agreement with a second…

Using the numerical diagonalization method, we examine the one-dimensional t_1-t_2-J_1-J_2 model (zigzag chain t-J model) which represents an effective model for metallic CuO double chain in the superconductor Pr_2Ba_4Cu_7O_15-\delta. Based…

The ground state and excitation spectra of the $S=1$ Heisenberg spin chain with hole hopping are investigated by means of the numerical-diagonalization method and by the help of the Zhang-Arovas picture. As for the charge sector, two phases…

We study the ground state of the one-dimensional "$t$-$J_s$-$J_{\tau}$ model," which is a variant of the $t$-$J$ model with additional channel degree of freedom. The model is not only a generalization of the $t$-$J$ model but also an…

Using the factorization of the wavefunction in the t-J-J'-model at small exchange couplings, we demonstrate the connection between the existence of a spin gap and an hc/2e flux periodicity of the ground state energy. We conjecture that all…

The one-dimensional t-J model with density-density repulsive interactions is investigated using exact diagonalization and quantum Monte Carlo methods. A short-range repulsion pushes phase separation to larger values of J/t, and leads to a…

The energies of singlet stripe phases in which a plane is broken up into spin liquid ladders by lines of holes, is examined. If the holes were static then patterns containing spin liquids with a finite spin gap are favored. The case of…

We study the t-J model in one dimension by numerically projecting the true ground state from a Luttinger liquid trial wave function. We find the model exhibits Luttinger liquid behavior for most of the phase diagram in which interaction…