Orbital current patterns in doped two-leg Cu-O Hubbard ladders
Piotr Chudziński, M. Gabay, Thierry Giamarchi
In the weak-coupling limit, we investigate two-leg ladders with a unit cell containing both Cu and O atoms as a function of doping. For purely repulsive interactions, using bosonization, we find significant differences with the single-orbital case: a completely massless quantum critical regime is obtained for a finite range of carrier concentration. In a broad region of the phase diagram, the ground state consists of a pattern of orbital currents plus a density wave. NMR properties of the Cu and O nuclei are presented for the various phases.
arXiv:0804.2779•Physical Review B•Aug 28, 2008•32 citations