13 papers
Magnetic order in ferromagnetically coupled spin ladders
S. D. Dalosto, J. Riera
A model of coupled antiferromagnetic spin-1/2 Heisenberg ladders is studied with numerical techniques. In the case of ferromagnetic interladder coupling we find that the dynamic an…
Study of impurities in spin-Peierls systems including lattice relaxation
P. Hansen, D. Augier, J. Riera +1
The effects of magnetic and non-magnetic impurities in spin-Peierls systems are investigated allowing for lattice relaxation and quantum fluctuations. We show that, in isolated cha…
Hole-Pairs in a Spin Liquid: Influence of Electrostatic Hole-Hole Repulsion
C. Gazza, G. Martins, J. Riera +1
The stability of hole bound states in the t-J model including short-range Coulomb interactions is analyzed using computational techniques on ladders with up to sites.…
Rapid Suppression of the Spin Gap in Zn-doped CuGeO_3 and SrCu_2O_3
George Martins, Elbio Dagotto, José Riera
The influence of non-magnetic impurities on the spectrum and dynamical spin structure factor of a model for CuGeO is studied. A simple extension to Zn-doped …
Exact diagonalization study of the two-dimensional t-J-Holstein model
A. Dobry, A. Greco, S. Koval +1
We study by exact diagonalization the two-dimensional t-J-Holstein model near quarter filling by retaining only few phonon modes in momentum space. This truncation allows us to inc…
On the Liaison Between Superconductivity and Phase Separation
Stephan Haas, Elbio Dagotto, Alexander Nazarenko +1
Models of strongly correlated electrons that tend to phase separate are studied including a long-range 1/r repulsive interaction. It is observed that charge-density-wave states bec…