Pairing and density correlations of stripe electrons in a twodimensional antiferromagnet
Abstract
We study a onedimensional (1D) electron liquid embedded in a 2D antiferromagnetic insulator, and coupled to it via a weak antiferromagnetic spinexchange interaction. We argue that this model may qualitatively capture the physics of a single charge stripe in the cuprates on length and time scales shorter than those set by its fluctuation dynamics. Using a local meanfield approach we identify the lowenergy effective theory that describes the electronicspin sector of the stripe as that of a sineGordon model. We determine its phases via a perturbative renormalizationgroup analysis. For realistic values of the model parameters we obtain a phase characterized by enhanced spin density and composite chargedensitywave correlations, coexisting with subleading triplet and composite singletpairing correlations. This result is shown to be independent of the spatial orientation of the stripe on the square lattice. We argue that slow transverse fluctuations of the stripes tend to suppress the density correlations, thus promoting the pairing instabilities. The largest amplitudes for the composite instabilities appear when the stripe forms an antiphase domain wall in the antiferromagnet. For twisted spin alignments the amplitudes decrease and leave room for a new type of composite pairing correlation, breaking parity but preserving timereversal symmetry.
 Publication:

Physical Review B
 Pub Date:
 December 2003
 DOI:
 10.1103/PhysRevB.68.214507
 arXiv:
 arXiv:condmat/0301585
 Bibcode:
 2003PhRvB..68u4507J
 Keywords:

 71.27.+a;
 71.10.Hf;
 74.20.Mn;
 Strongly correlated electron systems;
 heavy fermions;
 NonFermiliquid ground states electron phase diagrams and phase transitions in model systems;
 Nonconventional mechanisms;
 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Superconductivity
 EPrint:
 Revtex, 28 pages incl. 5 figures