2 research outputs found
Phase diagram of the three band half-filled Cu-O two-leg ladder
We determine the phase diagram of the half-filled two-leg ladder both at weak
and strong coupling, taking into account the Cu d_{x^2-y^2} and the O p_x and
p_y orbitals. At weak coupling, renormalization group flows are interpreted
with the use of bosonization. Two different models with and without outer
oxygen orbitals are examined. For physical parameters, and in the absence of
the outer oxygen orbitals, the D-Mott phase arises; a dimerized phase appears
when the outer oxygen atoms are included. We show that the circulating current
phase that preserves translational symmetry does not appear at weak coupling.
In the opposite strong-coupling atomic limit the model is purely electrostatic
and the ground states may be found by simple energy minimization. The phase
diagram so obtained is compared to the weak-coupling one.Comment: 10 pages, 5 figures, Version accepted for publication in PR