Abstract
We study, using a perturbative renormalization group technique, the phase diagrams of bond-aligned and diagonal Hubbard ladders defined as sections of a square lattice with nearest-neighbor and next-nearest-neighbor hopping. We find that for not too large hole doping and small next-nearest-neighbor hopping, the bond-aligned systems exhibit a fully spin-gapped phase while the diagonal systems remain gapless. Increasing the next-nearest-neighbor hopping typically leads to a decrease of the gap in the bond-aligned ladders, and to a transition into a gapped phase in the diagonal ladders. Embedding the ladders in an antiferromagnetic environment can lead to a reduction in the extent of the gapped phases. These findings may suggest a relation between the orientation of hole-rich stripes and superconductivity as observed in La2-x Srx Cu O4.
Original language | American English |
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Article number | 184503 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 71 |
Issue number | 18 |
DOIs | |
State | Published - 2005 |