41 research outputs found
Effect of on-site Coulomb repulsion on phase transitions in exactly solved spin-electron model
A hybrid lattice-statistical model on doubly decorated planar lattices, which
have localized Ising spins at their nodal lattice sites and two itinerant
electrons at each pair of decorating sites, is exactly solved by the use of a
generalized decoration-iteration transformation. Our main attention is focused
on an in uence of the on-site Coulomb repulsion on ground-state properties and
critical behavior of the investigated system.Comment: 2 pages, 3 figures, presented at 14th Czech and Slovak Conference on
Magnetism 6.-9. July 2010, Kosice, Slovaki
Spin-1/2 XXZ diamond chain within the Jordan-Wigner fermionization approach
The spin-1/2 XXZ diamond chain is considered within the Jordan-Wigner
fermionization. The fermionized Hamiltonian contains the interacting terms
which are treated within the Hartree-Fock approximation. We obtain the
ground-state magnetization curve of the model for some particular cases and
compare the results with the exact diagonalization data for finite chains of 30
spins and known exact results. We also analyze the validity of the suggested
approximation.Comment: 2 pages, 1 figure, presented at 14th Czech and Slovak Conference on
Magnetism 6.-9. July 2010, Kosice, Slovaki